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Blood Sweat Tears and Grease => Projects => Cafe Racers => Topic started by: Hurco550 on Jun 22, 2016, 20:39:36

Title: Yamaha rd350 Road Racer Liquid Cooled!!
Post by: Hurco550 on Jun 22, 2016, 20:39:36
Well, I cut down my project pile in favor of an rd350, some chambers and a cool old school road race fairing. Got rid of my hs1 90 Yamaha and gt380 basket case.

(http://uploads.tapatalk-cdn.com/20160622/71e8b85b1f51dd65bbaf0fb7e966c993.jpg)

Came home with this.
(http://uploads.tapatalk-cdn.com/20160622/8a38cda5c250371b1652c1371466dc60.jpg)

(http://uploads.tapatalk-cdn.com/20160622/0d7bd792752b3b1429997a8ebf25a6b2.jpg)

(http://uploads.tapatalk-cdn.com/20160622/587cecab79fbd3947c0a026495507ce3.jpg)

Plan is simple in theory. No creature comfort, road race style bike, barely legal. Ported r5 motor with the 6 speed rd350 transmission. More to come, hopefully since this is now my only bike project, I can keep this one going.
Title: Re: Yamaha rd350 road racer
Post by: stroker crazy on Jun 22, 2016, 22:43:08
Now you're talking!

Looks like the shocks need an upgrade …

Crazy
Title: Re: Yamaha rd350 road racer
Post by: davedogg on Jun 22, 2016, 23:07:22
I have some random RD parts laying around. Let me know if you need some.

-Dave
Title: Re: Yamaha rd350 road racer
Post by: themxracer121 on Jun 22, 2016, 23:18:49
Awesome I've got a similar plan in mind for my next project!  I like the full fairings on the RD too

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Title: Re: Yamaha rd350 road racer
Post by: teazer on Jun 23, 2016, 00:33:25
Sounds like a plan.  400 box is even better if you can find one at the right price, and of not 350 trans will work too.  Fit a decent ignition  (anything but points) and you should be good to go.
Title: Re: Yamaha rd350 road racer
Post by: canyoncarver on Jun 23, 2016, 00:37:37
Nice, I'm glad it's a keeper.
Title: Re: Yamaha rd350 road racer
Post by: Hurco550 on Jun 23, 2016, 00:38:34
Sounds like a plan.  400 box is even better if you can find one at the right price, and of not 350 trans will work too.  Fit a decent ignition  (anything but points) and you should be good to go.
If you don't mind, I'll probably pick your brain a bit during this project. Word on the street is that you know a thing or two about 2strokes and road racing :)
Title: Re: Yamaha rd350 road racer
Post by: teazer on Jun 23, 2016, 01:37:11
You may have heard that from my publicist who is truly a great man and everyone loves him, and he has been incredibly successful.......   Too much election coverage for one day..

PM me any time.
Title: Re: Yamaha rd350 road racer
Post by: Shoeman on Jun 23, 2016, 07:20:39
For better driveability, use the RD cylinders over the piston-port R5.  The reed valves make for a much more enjoyable experience.  Teazer is correct on the 400 trans too.  Closer ratios in the top gears.  Are those Bassani pipes? 
Title: Re: Yamaha rd350 road racer
Post by: Hurco550 on Jun 23, 2016, 11:13:12
For better driveability, use the RD cylinders over the piston-port R5.  The reed valves make for a much more enjoyable experience.  Teazer is correct on the 400 trans too.  Closer ratios in the top gears.  Are those Bassani pipes?

I think I'll stick with the Rd gear box for now, only because I have it available, and monies need to be spent elsewhere on the project lol I'm not opposed to the reed motor per say either, I think I'll start by tearing them both down and seeing what I have
Title: Re: Yamaha rd350 road racer
Post by: JustinLonghorn on Jun 23, 2016, 11:59:14
Dig it.
Title: Re: Yamaha rd350 road racer
Post by: Hurco550 on Jun 23, 2016, 17:58:34
For better driveability, use the RD cylinders over the piston-port R5.  The reed valves make for a much more enjoyable experience.  Teazer is correct on the 400 trans too.  Closer ratios in the top gears.  Are those Bassani pipes?
And I can't find any markings on the pipes, but the guy I got them from said they are just dg's
Title: Re: Yamaha rd350 road racer
Post by: Shoeman on Jun 23, 2016, 18:55:21
I'm thinking they're not DG.  DG have a single stage diffuser, and yours have a two stage.  Much better.     
Title: Re: Yamaha rd350 road racer
Post by: Hurco550 on Jun 24, 2016, 01:52:04
Started pulling down the r5 motor to see what I'm working with. Got one side freed up without much fuss, the other side isn't being quite so easy. If my concoction doesn't work, I'll grab some atf and acetone tomorrow, 70% of the time, it works every time. I won't know until it gets torn clear down if it needs a full crank rebuild, but odds are it will. I found this online, and I doubt you can rebuild one for the price of this new. That said, I think the country of origin is Taiwan, and I cannot find any user reviews. $400 for a new crank almost seems to cheap in a way.
https://www.vitosperformance.com/atv_parts/product.php?productid=11577&cat=0&page=&featured=Y

I'm going to tear the rd350 motor down as well to see where I stand on the two, but the top end is stuck on it as well.

While I wait for funds to build a motor, I will try to mount the fairing, sort the tank and seat, and figure the chassis work. I think a cb500t tank will fit the bill, but I can't bring myself to strip the paint off this tank, it's just to nice. Anyhow, just a mockup, so don't bind your panties ;)
(http://uploads.tapatalk-cdn.com/20160623/83f39e2f6034b5904b0e991ef01a10bd.jpg)
Title: Re: Yamaha rd350 road racer
Post by: Shoeman on Jun 24, 2016, 07:22:26
$400 is cheap for sure.  I had not looked at Vitos website in many years, since I sold my last RZ.  He's expanded his product line quite a bit.  Hard to say no at that price.  I'd find out about the return policy and if allowed, I'd get one, measure it to make sure it meets Yam spec on all dimensions before using it.  Good calipers, some v-blocks and dial indicator(s) is all you need.
  I see he sells a racing version too (TR) that uses the TZ style roller bearing on the primary end but does not have the lightening holes of the true race cranks, for more money.  Not worth the extra $$ for a street bike though.
Title: Re: Yamaha rd350 road racer
Post by: advCo on Jun 24, 2016, 07:47:26
Rad. That fairing is sweet. I'm in.


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Title: Re: Yamaha rd350 road racer
Post by: TranceMachineVienna on Jun 24, 2016, 10:08:32
Did i really miss this?epic!
Title: Re: Yamaha rd350 road racer
Post by: teazer on Jun 24, 2016, 10:41:50
....................
  I see he sells a racing version too (TR) that uses the TZ style roller bearing on the primary end but does not have the lightening holes of the true race cranks, for more money.  Not worth the extra $$ for a street bike though.

TZ outer main bearings are much better than the street bearings but cannot be used on a crank with helical primary gears.  They must be straight cut to use them because unlike balls, they can't take the side loads.  So TZ cranks for bikes with straight cut primaries and dry clutch and regular bearings for street bikes with helical gears and wet clutch.
Title: Re: Yamaha rd350 road racer
Post by: teazer on Jun 24, 2016, 10:43:11
I know we all have a different sense of style, but please remove that tank and put it on something fat and heavy - like say a Honda.... :-) 
Title: Re: Yamaha rd350 road racer
Post by: TranceMachineVienna on Jun 24, 2016, 10:53:35
I know we all have a different sense of style, but please remove that tank and put it on something fat and heavy - like say a Honda.... :-)

+1.....that got me a good laughing fit.
Title: Re: Yamaha rd350 road racer
Post by: Hurco550 on Jun 24, 2016, 10:57:42
Great to know about the crank and side load on the bearings! And the tank.... I had it on the wall so I sat it in there ha.  When the right deal comes along I'll pick up a property tail section and tank. I'll see what mid Ohio has in store
Title: Re: Yamaha rd350 road racer
Post by: VonYinzer on Jun 24, 2016, 11:10:44
Great to know about the crank and side load on the bearings! And the tank.... I had it on the wall so I sat it in there ha.  When the right deal comes along I'll pick up a property tail section and tank. I'll see what mid Ohio has in store

I have a couple glass race seats on the shelf. Different designs but both vintage "cafe racer" style. I'll get you some pics when I get back into town Monday if you're interested.
Title: Re: Yamaha rd350 road racer
Post by: Shoeman on Jun 24, 2016, 11:22:28
TZ outer main bearings are much better than the street bearings but cannot be used on a crank with helical primary gears.  They must be straight cut to use them because unlike balls, they can't take the side loads.  So TZ cranks for bikes with straight cut primaries and dry clutch and regular bearings for street bikes with helical gears and wet clutch.
All true.  I used to use Tz bearings everywhere but the primary side.  Makes for a strong crank but overkill for street use. 
Title: Re: Yamaha rd350 road racer
Post by: Hurco550 on Jun 24, 2016, 11:51:59
I have a couple glass race seats on the shelf. Different designs but both vintage "cafe racer" style. I'll get you some pics when I get back into town Monday if you're interested.
Sure thing man, that would be great!
Title: Re: Yamaha rd350 road racer
Post by: clem on Jun 25, 2016, 00:38:31
Some people hate the Vito cranks and some dig them. I read about a guy that put a couple thousand miles on one and said it was still fine. Another put a couple hundred and said the vibration was picking up. I had Mr. Garland rebuild my crank and he did an excellent job. Yeah I've missed a few shifts that went past 10k and I try to ring its neck now and again and it still feels solid.

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Title: Re: Yamaha rd350 road racer
Post by: teazer on Jun 25, 2016, 02:22:51
We shift at 10,500 on a 350 with heavy pistons and a little more on a 250 and cranks last as long as they have the right rods and we don't hydro lock motors and try to start them on rollers - that bends rods which then rub on crank wheels until they get hot enough to snap.  Not a pretty sight.

Lynn Garland is an all round good guy and very experienced builder of Yamaha twins.
Title: Re: Yamaha rd350 road racer
Post by: Shoeman on Jun 25, 2016, 08:45:24
Lynn Garland is an all round good guy and very experienced builder of Yamaha twins.
Yes indeed.  We used to share garage space at NHIS during USCRA races.  A very distinguished gentleman with a fine collection of Yam race bikes.   An added bonus was the fact that he is friends with Kevin Cameron, who would stop by and visit our pit on occasion.  Man, those were the days. 
Title: Re: Yamaha rd350 road racer
Post by: Sav0r on Jun 25, 2016, 14:22:22
I have a Vito's in my RD now. Seems fine but I don't have a lot of miles on it quite yet. I'll rebuild my OEM crank in the offseason with the hope of eventually having a complete seciond engine eventually. For the price of the Vito's though it really can't be beat in my opionion. Especially as a drop in unit, and there is something awfully nice about it just showing up and dropping it in. That said, if I were going racing where I'd be expecting to run flat out in the upper 20% of the RPM range all of the time I think I'd stick with a well serviced OEM unit.
Title: Re: Yamaha rd350 road racer
Post by: alzcbz on Jun 25, 2016, 17:18:23
Vito's does a lot of Blaster and Banshee mods. RD350 mods are common for the Banshees. Very reputable, never heard bad about their products, not to mention they are somewhat local to me.
Title: Re: Yamaha rd350 road racer
Post by: Hurco550 on Jun 27, 2016, 12:13:23
Thanks for the replies on the crank. There is currently a nos crank that I'm trying to get my paws on, if not I'll probably try to grab one of those new vitos. I'm also on the prowl for an electronic ignition. Trying to decide if I should go with the full setup with stator, coils and all ($$) or just one to delete the points. For now, until I get some scratch to really build the motor, I'm gonna try to get the chassis straight. Nothing special for now. Trying to track some aluminum hoops to lace on, tapered neck bearings fork seals ect... should also probably track down some rear socks as well. Also gonna work to make the proper mounts for the fairing.

I'm not planning to build this motor to the ragged edge on tuning, but I have read that there is plenty of unlocked power in these things with some tuning,so we shall see where she ends up. Planning to grab an fzr rotor from vonyinzer to fit to the front and help with the whoa as well.
Title: Re: Yamaha rd350 road racer
Post by: teazer on Jun 27, 2016, 13:19:52
Match that new rotor with almost any modern 2 piston sliding caliper and the thing will stand on its nose.

DYNA S is cheaper and allows you to keep the stock lights and charging system.

Motoplat/FEMSA/Hitachi/PVL/ etc is best for track but no charging circuits.

Powerdynamo is a great compromise for the street but not cheap either.

How will the bike be used?  Street/touring/track days?  May help to decide on ignition to suit.
Title: Re: Yamaha rd350 road racer
Post by: jpmobius on Jun 27, 2016, 23:31:34
I'll second the PowerDynamo system as a good choice.  Personally, I like a Banshee system better, but it is a real PITA to implement as you need to build a Frankenstein crank to accept the permanent magnet stator and the ignition trigger does not fit inside a stock Rd case cover.  The PowerDynamo system is nearly identical but is a much bigger hassle to adjust the ignition timing.  It is fine once you do set it, and the charging/power supply is huge improvement over the old RD system.  It is a bit pricey, but you do get a lot of hardware and can easily run with no battery as the charging system and ignition system are completely independent.
Title: Re: Yamaha rd350 road racer
Post by: davedogg on Jun 27, 2016, 23:37:07
There's nothing wrong with points. Save the money and put it towards something else. BTW I have stock shocks in decent shape for cheap.
Title: Re: Yamaha rd350 road racer
Post by: jpmobius on Jun 27, 2016, 23:59:07
Agreed.  My driver RD is 100% stock.  Points and charging.  Coils are replica original - the OEM ones are crap and were when new.  Runs like a top, but the charging system is anemic (even when tuned to perfection). The rotors are doomed to failure if you lean on the motor and are now getting scarce (ish), which is the best (IMHO) reason for swapping out to a more modern system.  Points are GREAT  on a mostly stock engine if you replace the coils and are ok with the normal tune up regimen.   
Title: Re: Yamaha rd350 road racer
Post by: Shoeman on Jun 28, 2016, 07:12:28
And I'll add that IMHO there is no real need to update to alloy rims.  Put the money into shocks and upgraded swingarm bushings along with the tapered steering head bearings you already mentioned.   Everybody's input on points and coils is dead on for a streeter.  Some mild porting and head work along with the pipes you have will wake it right up for not much money, even with the stock carbs.
 
Title: Re: Yamaha rd350 road racer
Post by: teazer on Jun 28, 2016, 12:17:08
And there are other opinions...  I wouldn't leave points on anything more than lawn equipment.  Maybe I'm just lazy and like the convenience of ignitions that are stone axe reliable and don't wear and change timing.  I love to build and ride bikes, I just hate to do maintenance.

Alloy rims are nice but the difference is small on a street bike, agreed but they do look good when the cash is available for an upgrade at some future date.
Title: Re: Yamaha rd350 road racer
Post by: Hurco550 on Jun 28, 2016, 12:42:53
All good points to be taken into consideration. I really appreciate the feedback guys! The direction in my mind for this is to be in spirit close to a street legal race bike, but that said, I'm far from a purist, and I'm not the kind of guy that will spend 200 bucks for a period correct bolt or something silly like that. I also don't want to tune it past the ledge of reliability. I would like to come as close as I can to building the motor right the first time as far as porting ect, though I know a two smoke just lives for the day it gets to finally grenade on you lol. 

For now, I think a good point was made on the wheels, but, I may possibly have a set coming to me for little to no coin, in which case I'll lace them.

The ignition is still something I'd like to do, as I don't enjoy fussing with points, that said, money will be spent on the crank and pistons first and I can always do that later on when funds build back up.

I'm not building this thinking that it will be a low budget thing and I know I'll have to spend some cash to make it right, but, I don't have a pile right now, so it will have to be done in stages.

I've been reading up on squish dimensions lately. I'm a welder and machinist by trade, so I'm planning on trying to tackle that on my own.

I have my eye on a crank, I'm trying to decide which banshee pistons to order, and sort the reeds. There are a number of piston options out there and I'm trying to decide where to go out which would best suit this build

Again, thanks for you input so far, I really appreciate the wealth of knowledge that has presented itself here already!
Title: Re: Yamaha rd350 road racer
Post by: Hurco550 on Jun 28, 2016, 12:49:53
There's nothing wrong with points. Save the money and put it towards something else. BTW I have stock shocks in decent shape for cheap.
Pm sent
Title: Re: Yamaha rd350 road racer
Post by: TranceMachineVienna on Jun 28, 2016, 12:52:35

I've been reading up on squish dimensions lately. I'm a welder and machinist by trade, so I'm planning on trying to tackle that on my own.

I have my eye on a crank, I'm trying to decide which banshee pistons to order, and sort the reeds. There are a number of piston options out there and I'm trying to decide where to go out which would best suit this build

Again, thanks for you input so far, I really appreciate the wealth of knowledge that has presented itself here already!

with the support of a good friend i managed to modify the squish on my RD and it makes a good difference to the performance before.
I used 350 LC pistons (i have reed valves), converted my stock RD carbs back to R5 specs (needles and needle jets),running 185´s mains with KN filter and DG pipes,it runs dang fine, just explored how easily those smokers wheel...its a blast ;-)
Title: Re: Yamaha rd350 road racer
Post by: farmer92 on Jun 28, 2016, 13:51:54


I've been reading up on squish dimensions lately. I'm a welder and machinist by trade, so I'm planning on trying to tackle that on my own.
Toroidal chambers too?
Title: Re: Yamaha rd350 road racer
Post by: teazer on Jun 28, 2016, 14:08:17
I love the shape but results don't seem to be there - at least not documented.  Do you have any data or back to back comparisons of torroidal versus flat or semi hemi designs? That I would like to see.
Title: Yamaha rd350 road racer
Post by: farmer92 on Jun 28, 2016, 16:58:46
I would think you would get a tiny bit more surface area, and thus marginally better cooling, but that's just speculating...
I doubt there is really any other advantage over hemispherical heads other than getting to say you built custom toroidal heads
Title: Re: Yamaha rd350 road racer
Post by: Hurco550 on Jun 29, 2016, 23:51:25
I did some reading on those, and they do seem cool, but I'm leaning towards a flat design, as I'll be doing it on an old south Bend 9
Title: Re: Yamaha rd350 road racer
Post by: teazer on Jun 30, 2016, 02:44:05
I would think you would get a tiny bit more surface area, and thus marginally better cooling, but that's just speculating...
I doubt there is really any other advantage over hemispherical heads other than getting to say you built custom toroidal heads

You actually need the smallest surface area for a given volume to reduce energy transfer as heat.

The idea is that the spark starts closer to the center of the hemispherical chamber which should lead to a faster and more complete burn and more power.  The last TZ250 motors used flat topped heads and the idea there was supposedly to leave a small annular pocket of unburned gas to act as a coolant to allow higher compression before detonation kicks in.

On a street motor I think I'd optimize MSV in the squish band and go with a conventional hemi head shape.  Peg the heads to the bores and seal them with TZ O rings
Title: Re: Yamaha rd350 road racer
Post by: Hurco550 on Jun 30, 2016, 14:30:00


On a street motor I think I'd optimize MSV in the squish band and go with a conventional hemi head shape.  Peg the heads to the bores and seal them with TZ O rings

By pegs you mean dowel pinned? Also, do you have a source for the tz o rings? I assume that also means an o ring groove would need to be machined into the head?

Title: Re: Yamaha rd350 road racer
Post by: teazer on Jun 30, 2016, 15:26:31
Yes Dowels.  I used to order my TZ O rings from my local dealer, but I'd probably just look on line for any of the cool head Banshee O rings.  Groove can be in block or head - whichever has most material available.

Remember that O ring grooves are not round, they are "square" to allow the ring to deform into.

http://www.qualityseals.com/pdfs/groovedesignandoringinstallation.pdf

http://o-ring.info/en/technical%20manual/ERIKS%20-%20Technical%20Manual%20-%20O-Ring%20Gland%20Design%20Information.pdf

Chuck Quenzler at Supertune has details on his web site http://imageevent.com/supertune/rd350enginebuildpics
http://imageevent.com/supertune/cncpics     http://imageevent.com/supertune/rddocumentstuff

Title: Re: Yamaha rd350 road racer
Post by: MickyC on Jul 01, 2016, 22:44:05
Smokey, looking good mate


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Title: Re: Yamaha rd350 road racer
Post by: Hurco550 on Jul 03, 2016, 19:27:37
Thanks for the links teazer! I'm planning on drawing those chambers up soon also!

I am planning on grabbing one of those vitos cranks and some banshee poisons soon.

Been having a hard time breaking the piston loose. No manner of heat, ice, oil, wood drift and hammer ect ect. Would free this thing. I decided to try to pump it full of grease.

Used a 1/2--13 bolt, drilled a hole through it and tig welded in a grease jerk.

(http://uploads.tapatalk-cdn.com/20160703/3045a7b8c5ccf1d974b5a0fda2a0e2b4.jpg)

Just barely wouldn't slide through the spark plug hole, so I had to turn a smudge off in the lathe.
(http://uploads.tapatalk-cdn.com/20160703/6ea9c51d03a243c440a9e787827acf32.jpg)

O rings to seal it, bolted the head on and started pumping.
(http://uploads.tapatalk-cdn.com/20160703/20f8eaba5e646d2ec6320aacc38f0ea1.jpg)

(http://uploads.tapatalk-cdn.com/20160703/e6ec28117408546dd0b7094d36483e8d.jpg)

(http://uploads.tapatalk-cdn.com/20160703/3704cafd1bd85844fdf941321a2cee13.jpg)

Was a messy way to do it, but it pushed it right out until the exhaust port opened up.

(http://uploads.tapatalk-cdn.com/20160703/670bf78823b524e0c4dfb88a60dbd35f.jpg)

(http://uploads.tapatalk-cdn.com/20160703/6249252f5abca98fe43dffdac7d46460.jpg)

(http://uploads.tapatalk-cdn.com/20160703/808fc9b1ebc612faa48853f5ef4b9460.jpg)

Though I won't make perhaps the power, right now the r5 piston port motor is in much better nick, so that's what I'll probable go with, and use the rd350 6 speed gear box.
Title: Re: Yamaha rd350 road racer
Post by: jpmobius on Jul 03, 2016, 20:27:46
You can make plenty of power with the piston port motor.  Drivability is the problem.  I had one in a drag bike doing sure enough high 10's in the quarter.  Wouldn't run hardly below 3 grand (hard to start!), but very strong on the big end.  If I could have gotten the clutch to work half way right more than once in a blue moon it would have gone faster.  Useless for the street, but the power is potentially there.  Plus I think there is some appeal from the simplicity alone, and I think they sound better!
Title: Re: Yamaha rd350 road racer
Post by: ridesolo on Jul 05, 2016, 17:10:15
Glad that finally came apart for you.  Damn messy way to go, but in the long run if it worked after all else failed I guess it's worth it.  Too bad we didn't think to turn that lump over and let it sit there in that pot of boiling oil!  Hope you at least got some french fries out of that mess!   :D
Title: Re: Yamaha rd350 road racer
Post by: Hurco550 on Jul 05, 2016, 18:21:44


BTW I have stock shocks in decent shape for cheap.

Shocks came in, good nick as described! Thanks man!
Title: Re: Yamaha rd350 road racer
Post by: davedogg on Jul 06, 2016, 13:50:46
No problem.  Good idea with the grease.  Let's see some smoke!
Title: Re: Yamaha rd350 road racer
Post by: Hurco550 on Jul 07, 2016, 17:12:50
Not much to update really, besides  receiving fork seals and neck bearings in the mail. Von yinzer left a pile of xs650 parts in my garage, and as a rent payment, I'll be rebuilding my front end with his  34mm tubes in place of the crusty ones currently on the Rd chassis.

(http://uploads.tapatalk-cdn.com/20160707/84c3922c119475abf53f8b603cead3e4.jpg)
(http://uploads.tapatalk-cdn.com/20160707/3b75855f4726eabf37a61ad2b285eed8.jpg)
 
I dig the fairing, but it looks pretty good with the r5 body works on it too.
(http://uploads.tapatalk-cdn.com/20160707/d68be1e07df362f011eed0730908ceb8.jpg)

Still trying to get the specs I need to build the motor I want. Trying to explain it is harder. Basically, it will be a street bike, but a toy. I don't expect this to be my daily rider, but I want to be able to do an hour or so ride when I can to a vintage bike night or the Sunday ride to the twistys ect. I just know (er have heard) that these motors have plenty of power to unlock, but I don't want it to be completely useless on the street. It may see a track now and again, for fun, not competition, and a track only bike is not the end goal. I want a zippy bike to go have the kinda fun you can have on a two stroke ripping around the roads, but I don't want to be so close to the edge that I can't ride it and i don't want to only make power over 10k rpm. I think that is possible on this bike, and I appreciate you guys that have already helped me in trying to know what to do to obtain it. Will be slow going for the next couple weeks, as I'm taking a vacation for a few weeks to the hot, sweaty dirty south, but I still have this project on the front of my mind. Headed to mid Ohio tomorrow as well to see what kind of goodies I can drag home as well.

Title: Re: Yamaha rd350 road racer
Post by: julian.allard66 on Jul 07, 2016, 17:37:28
Sounds like you want a road tune for it, start by getting the squish right and then change the ports if you feel the need, on UK pump petrol 0.9 mm used to be the right squish, but it'd probably need to be more than that on modern US fuel as it has a high ethanol content
Title: Re: Yamaha rd350 road racer
Post by: Redbird on Jul 07, 2016, 17:53:29
Subscribed.

I've got odd and end spare parts from my DS7 build. Holler if you need anything ;)
Title: Re: Yamaha rd350 road racer
Post by: teazer on Jul 07, 2016, 19:18:41
Ports on those motors are relatively mild in terms of port timing and width and there is a lot of room to improve things without going stark raving mad.  You don't want a race tune with powerband from 9,000 to 10,500 and nothing either side.  You can go beyond a mild tune though as long as you keep the end objective in mind.

What's up with that pipe?  It looks as if it is very low compared to most RD pipes.  It could just be a badly shaped header pipe.
Title: Re: Yamaha rd350 road racer
Post by: davedogg on Jul 07, 2016, 23:32:33
My RD's are very reliable and enjoyable. Stock is fun. I've taken my modified 350 and stock 400 on 100 + trips. But there are simple add ons to unleash some power. My experienced tuner just rode my bike the other week and was impressed (so I know I did things right)  This may be overkill but here are some performance mods I did to get you started:

2 into 1 K&N Y boot (more air) ~$90
Dave F/ Dale A carb mod (more air needs more gas) I'm not an expert. I just know it works.
RZ/Banshee crossover manifold and tube (erases flat spot around 5k) ~$50
YZ125 Reeds petals (consensus for better low end torque) ~$40
Heads squished and o-ring (better compression = more power) look up Scott Clough Racing ~$190
Good set of pipes. DG's are ok. I would get SpecII ~$500-700

Using both Wiseco (forged) and ProX (cast) pistons I like the ProX more. I'm sure there is more but this is all I can think of off the top of my head.
Title: Re: Yamaha rd350 road racer
Post by: Hurco550 on Jul 08, 2016, 20:20:38
Subscribed.

I've got odd and end spare parts from my DS7 build. Holler if you need anything ;)
Thanks a million man, I may hit you up sometime

What's up with that pipe?  It looks as if it is very low compared to most RD pipes.  It could just be a badly shaped header pipe.

I have no idea. I thought that they seem like they hang awfully low as well. I was thinking it could be something about flow with a less sharp bend. I would shorten them, but besides the basics of how chambers work, I don't know how the changes will effect (for better or worse) performance by shortening the head pipes.
My RD's are very reliable and enjoyable. Stock is fun. I've taken my modified 350 and stock 400 on 100 + trips. But there are simple add ons to unleash some power. My experienced tuner just rode my bike the other week and was impressed (so I know I did things right)  This may be overkill but here are some performance mods I did to get you started:

2 into 1 K&N Y boot (more air) ~$90
Dave F/ Dale A carb mod (more air needs more gas) I'm not an expert. I just know it works.
RZ/Banshee crossover manifold and tube (erases flat spot around 5k) ~$50
YZ125 Reeds petals (consensus for better low end torque) ~$40
Heads squished and o-ring (better compression = more power) look up Scott Clough Racing ~$190
Good set of pipes. DG's are ok. I would get SpecII ~$500-700

Using both Wiseco (forged) and ProX (cast) pistons I like the ProX more. I'm sure there is more but this is all I can think of off the top of my head.
I should change the title of this thread, the frame is rd350, but the motor I'm using will be the piston port r5 motor. Thanks for all the great info though!
Title: Re: Yamaha rd350 road racer
Post by: Hurco550 on Jul 08, 2016, 20:29:09
Also, even though I know aluminum rims aren't a need, I picked these up at Mid Ohio for a song. Both 18's, rear is an akront and the front is a tasakaga. Got both for $20 bucks, so I couldn't pass em up, not for cool old high shoulder hoops
(http://uploads.tapatalk-cdn.com/20160708/225bcd0ffa268691ab9347d5ee732744.jpg)

(http://uploads.tapatalk-cdn.com/20160708/02e4e10e088ddb75d9d81e2834823a20.jpg)
Title: Re: Yamaha rd350 road racer
Post by: teazer on Jul 08, 2016, 21:20:36
Pipe lengths are critical on expansion chambers but until we look at the dimensions of that set of pipe, I wouldn't worry too much.  If necessary a new set of header could be bent up or those could be changed to suit.  It was just odd that they seemed so low.  Are the fitted to the barrel correctly or were they just a loose fit?

Those hoops will not work at all, but I will allow you to send them to me to spare you the embarrassment.....  Great find Slip a spare spoke into each and see if the are close to the right angle for a disk hub or drum hub.  Would be awesome if they are one of each.

And R5 carbs are the so called Dave F mod.  That's what he basically changed RD carbs to (more or less).  Y boot is good mod though.
Title: Re: Yamaha rd350 road racer
Post by: Hurco550 on Jul 17, 2016, 18:53:55
Have any of you guys used the banshee pistons in an r5 top end vs an rd350 top end? I can't imagine there would be an issue doing so, but I figured I'd ask
Title: Re: Yamaha rd350 road racer
Post by: davedogg on Jul 17, 2016, 19:04:02
Pretty sure you cannot use banshee pistons on a R5. The R5 is piston port and doesn't have the windows that the reed valve RD and banshees have.
Title: Re: Yamaha rd350 road racer
Post by: Hurco550 on Jul 17, 2016, 20:13:37
Pretty sure you cannot use banshee pistons on a R5. The R5 is piston port and doesn't have the windows that the reed valve RD and banshees have.
Well dang. Thanks for the info though man
Title: Re: Yamaha rd350 road racer
Post by: Redbird on Jul 17, 2016, 20:13:45
That's my understanding as well.
Title: Re: Yamaha rd350 road racer
Post by: Hurco550 on Jul 17, 2016, 20:14:55
Maybe I should build an Rd top end after all then, but teazer has already been putting a bunch of time into r5 port maps for me though
Title: Re: Yamaha rd350 road racer
Post by: clem on Jul 17, 2016, 22:01:51
The Banshee pistons do work in the RD350 but they need to be modified.  Good quality R5 pistons may be hard to find. I think that Wossner may be the best bet.

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Title: Re: Yamaha rd350 road racer
Post by: Hurco550 on Jul 17, 2016, 22:17:53
The Banshee pistons do work in the RD350 but they need to be modified.  Good quality R5 pistons may be hard to find. I think that Wossner may be the best bet.

Sent from my SAMSUNG-SM-G920A using DO THE TON mobile app (http://'https://siteowners.tapatalk.com/byo/displayAndDownloadByoApp?rid=89466')
I did read about filing of the tab on the intake side for the rd's,  I just assumed it would be the same for the r5,but it seems like that is not the case
Title: Re: Yamaha rd350 road racer
Post by: Hurco550 on Jul 18, 2016, 02:40:19


Good quality R5 pistons may be hard to find. I think that Wossner may be the best bet.

Sent from my SAMSUNG-SM-G920A using DO THE TON mobile app (http://'https://siteowners.tapatalk.com/byo/displayAndDownloadByoApp?rid=89466')

Wossner pistons are about $130 a pop. Seems steep to me, but maybe that's the going rate for a quality piston these days
Title: Re: Yamaha rd350 road racer
Post by: TranceMachineVienna on Jul 18, 2016, 09:52:18
This was one of the reaons i didnt buy a R5 cuz the pistons are really hard to get in Europe...I used on both of my RD stages (Stock 250 setup and modified 350) the pistons (Pro-X pistons) of the watercooled LC 350 (250)...they worked fine on the 250 and the 350 setup.
I still got my RD 250 jugs and pistons in my shelf, so if youre planning to go for that, let me know (shipping might be expensive from austria).

I also thought about going for Wossners but I went for Pro-X in the end, a friend explained to me that going for A to B in the city is not right thing for them (forged steel needs more time to warm up and i think its bored the lower play).
Title: Re: Yamaha rd350 road racer
Post by: Shoeman on Jul 18, 2016, 09:54:52
Maybe I should build an Rd top end after all then, but teazer has already been putting a bunch of time into r5 port maps for me though
Is he porting a set for you or just drawing port diagrams?   Here's basic RD setup for street use:   Raise exh port 1mm, widen it 2mm.   Widen the intake 2mm and remove the lip at the cylinder on the port floor.  Make sure both cylinders match when you're done. Leave the transfers alone unless you have a right angle hand piece.  Match the case top to the cylinder base if you like.   Cut the center tab off banshee Pistons as you already know bolt it back together and let it rip.
Title: Re: Yamaha rd350 road racer
Post by: teazer on Jul 19, 2016, 16:38:25
I'm just working up some porting options and looking at his pipes.  RD350 has basically the same ports as an R5 apart from the extra boost (intake/transfer) port.

That's a nice mild clean up Shoeman and would work well with his pipes.  They may need to have the headers shortened though. I'll run a few more numbers.

I agree that an RD350 top end would be preferable and pistons are readily available versus not so much on an R5.  Could use TZ350 pistons in an R5 on stock bores I guess but not a great choice for the street.
Title: Re: Yamaha rd350 road racer
Post by: Shoeman on Jul 19, 2016, 19:30:17
Teaser, are you calculating his pipes reflected (or tuned) length and seeing how that matches various exhaust port Timings?  I used to spend hours doing that sort of thing, first on paper using Jennings info, then later with TSR programs back in the Win95 days when those became available.  I don't know you but it sounds like you take a solid scientific approach, hats off to you. I quit the racing and tuning game quite awhile ago now but I was the same way and my motors won a lot of races and satisfied street guys too.   I'd add that in most cases like this, optimizing the pipe is not a necessity.  It will gain that last extra edge for sure but on a street bike it's a luxury. Unless of course the pipe is a torquer by design and the ports are set for higher revs than the pipes are.  The. You get a nasty powerband for sure
The reed valves and the 360deg intake timing they allow make a huge difference in how you can ride the RD vs the R5.  Much easier.  It's like power valve exhausts, the flexibility they gave was a real revelation back in the day.  Every generation of Yam got better. 
Title: Re: Yamaha rd350 road racer
Post by: stroker crazy on Jul 19, 2016, 20:53:01
Every generation of Yam got better.

+1!

Watercooling was a major help also.

Crazy
Title: Re: Yamaha rd350 road racer
Post by: Shoeman on Jul 20, 2016, 10:49:34
Absolutely.  With that development you could now maintain all that horsepower you had created.   Unless you blew it up 🙄
Title: Re: Yamaha rd350 road racer
Post by: teazer on Jul 20, 2016, 13:35:33
Teazer, are you calculating his pipes reflected (or tuned) length and seeing how that matches various exhaust port Timings?  I used to spend hours doing that sort of thing, first on paper using Jennings info, then later with TSR programs back in the Win95 days when those became available.  I don't know you but it sounds like you take a solid scientific approach, hats off to you. I quit the racing and tuning game quite awhile ago now but I was the same way and my motors won a lot of races and satisfied street guys too.   I'd add that in most cases like this, optimizing the pipe is not a necessity.  It will gain that last extra edge for sure but on a street bike it's a luxury. Unless of course the pipe is a torquer by design and the ports are set for higher revs than the pipes are.  The. You get a nasty powerband for sure
The reed valves and the 360deg intake timing they allow make a huge difference in how you can ride the RD vs the R5.  Much easier.  It's like power valve exhausts, the flexibility they gave was a real revelation back in the day.  Every generation of Yam got better. 

I have his pipe dimensions and a couple of pieces of software: Bimotion to work out target port sizes and MOTA to do the simulations.  last night MOTA started dropping out so I shut off the PC and this morning the power supply fan failed and started to smell and then ...nothing.  SO I just swapped in a new power supply and will try again this evening.

I then start to move the variables over a range to see the impact on the shape and size of the powerplot.   In this case the starting point is the pipes that he has with header changes and then a few simple port mods. I have a set of TZ750 barrels, off my last TZ350, if I need more inspiration.

Water cooling really helped them to stay together and on an RD350 there are all sorts of reed options.  An RZ350 has the same size reed cage as a TZ750.  The best is probably a YZ85 cage with a few subtle mods but for a mild motor stock cages and different reeds are enough.
Title: Re: Yamaha rd350 road racer
Post by: Hurco550 on Jul 28, 2016, 20:30:07
Man, I love hearing you guys that know your stuff talk!

Just got back in town. Went back up to the salvage yard where I got the bike in the first place, and picked up the important part.... he found the title so now I don't have to go the Vermont route! It's already open notorized to boot.
(http://uploads.tapatalk-cdn.com/20160728/eea889bf0af577207739e0b4ff4ffd89.jpg)

Also traded him one of the akront hoops for a xs650 high shoulder that should lace right up with out much issue. The one i traded was for a non symmetric hub (probably ducati) and wouldn't have laced right. I have to un lace this hub and give it back to him.
(http://uploads.tapatalk-cdn.com/20160728/92fac9ca11099a20475534ca1d12c4ab.jpg)
Title: Re: Yamaha rd350 road racer
Post by: irk miller on Jul 28, 2016, 20:59:40
I dunno why, but it's very satisfying to unlace a wheel with a pair of bolt cutters.
Title: Re: Yamaha rd350 road racer
Post by: Hurco550 on Jul 28, 2016, 21:03:44
I dunno why, but it's very satisfying to unlace a wheel with a pair of bolt cutters.
He wants the crusty old spokes back =/
Title: Re: Yamaha rd350 road racer
Post by: clem on Jul 28, 2016, 22:42:07
Of course one day he'll get around to re plating those old things.

Sent from my SAMSUNG-SM-G920A using DO THE TON mobile app (http://'https://siteowners.tapatalk.com/byo/displayAndDownloadByoApp?rid=89466')

Title: Re: Yamaha rd350 road racer
Post by: Hurco550 on Jul 28, 2016, 22:47:24
Of course one day he'll get around to re plating those old things.

Sent from my SAMSUNG-SM-G920A using DO THE TON mobile app (http://'https://siteowners.tapatalk.com/byo/displayAndDownloadByoApp?rid=89466')
Ha, this guy, well two brothers have been at the M.C. salvage business for years. NOTHING gets pitched, which is probably part of why they have over 700 bikes + gobs of parts. I remember my first trip over there. I needed some parts, one of which was a fuse box for a cb550.the old one was trashed, cracked plastic, broken tabs and what not. They had me bolt it on the parts bike in place of the one I got. Seriously, nothing gets thrown away there lol
Title: Re: Yamaha rd350 road racer
Post by: Sav0r on Jul 30, 2016, 01:02:27
Make sure you put your old steel rims on scale to compare to those shouldered set. Some shouldered rims can be damned heavy and those old steel units aren't as heavy as you might think. Tires of course make up the major rotating mass there, but every little bit helps.
Title: Re: Yamaha rd350 road racer
Post by: Hurco550 on Jul 30, 2016, 02:23:09
Make sure you put your old steel rims on scale to compare to those shouldered set. Some shouldered rims can be damned heavy and those old steel units aren't as heavy as you might think. Tires of course make up the major rotating mass there, but every little bit helps.
I'll look into that when I get them un laced, they were heavier than I expected when I picked them up. Bad thing is the steel hoops are in pretty shabby condition.

Thanks!
Title: Re: Yamaha rd350 road racer
Post by: Hurco550 on Jul 30, 2016, 02:29:02
Not a huge update, but I made up an arbor to do my squish machining when that time comes. I have yet to put an indicator on it to see if the plug holes are centered, as I've read that sometimes they aren't. I also still have to take a light mill cut off of the spark plug surface to make sure that it is true with the gasket surface before doing any machining.

I used a buddy's lathe to make the arbor. He is tooled up a bit better than I am at the moment, plus his lathe has a dro, which makes everything easier.

(http://uploads.tapatalk-cdn.com/20160729/7e5aafbff8ba9436591b14a14a903f3a.jpg)

(http://uploads.tapatalk-cdn.com/20160729/933a73bdf59c18cc8f10e31828adb771.jpg)

(http://uploads.tapatalk-cdn.com/20160729/db75cd3bf6bb362b9941e52492648a03.jpg)

I'll use my South Bend 9 when the time comes.
(http://uploads.tapatalk-cdn.com/20160729/d276ed50b82955322c1c5fd0dfbacb3b.jpg)

Didn't think about clearance of the bed, but I have a half inch, which is about a mile in machinist terms, so it's all good.
(http://uploads.tapatalk-cdn.com/20160729/0c16d3b6da82bc845d2848b9fb910f50.jpg)
Title: Re: Yamaha rd350 road racer
Post by: teazer on Jul 30, 2016, 11:29:27
That is looking very professional.  I need to get my machinist to make an arbor for our nexyt project to do exactly what you are doing there.
Title: Re: Yamaha rd350 road racer
Post by: Hurco550 on Jul 30, 2016, 16:10:29
THANKS!  I used a stud drilled and tapped into the arbor instead of single point threading. Luckily my buddy is a mechanic and had a 14mmx1.25 tap on his service truck and a harmonic balancer bolt of the same size and thread pitch to rob for the threaded lug.
Title: Re: Yamaha rd350 road racer
Post by: Hurco550 on Aug 04, 2016, 21:39:45
Again, not a ton to update, but I did get the tapered neck bearings fitted.
(http://uploads.tapatalk-cdn.com/20160804/3cd9bf39c6d9c52f1ffb87c532edc01d.jpg)
(http://uploads.tapatalk-cdn.com/20160804/9ba188e99776f9d8fb54bdc91946ebf5.jpg)

Xs650 forks mocked up. They are about 2 inches longer than the Rd units, so they have to go up through the top tree a bit. I thought about flipping the top tree upside down, but that looks pretty goofy.
(http://uploads.tapatalk-cdn.com/20160804/a3b1cc0c3831f5ea24cac0a9f25cf079.jpg)

What's you guys advice on the steering damper? Worth keeping? Not worth keeping? Does it even make a difference?
Title: Re: Yamaha rd350 road racer
Post by: irk miller on Aug 04, 2016, 21:45:32
Put that damper on your camera  :o whooooooaaaahhhhh  :-[
Title: Re: Yamaha rd350 road racer
Post by: Hurco550 on Aug 04, 2016, 21:56:23
Put that damper on your camera  :o whooooooaaaahhhhh  :-[
It worked.
(http://uploads.tapatalk-cdn.com/20160804/c8dd4cc5572b09a0e74e11d5638ce76d.jpg)
Title: Re: Yamaha rd350 road racer
Post by: Hurco550 on Aug 05, 2016, 10:38:06
Question on top triple design. Planning on making my own as I don't feel like dropping $235 on this one. I've seen a few like this with the steering stem pinch bolt deleted. How crucial is it to performance/ fork flex ect to keep it intact?
(http://uploads.tapatalk-cdn.com/20160805/998b81c6905b3f2fe562004d3cc507a2.jpg)
Title: Re: Yamaha rd350 road racer
Post by: irk miller on Aug 05, 2016, 11:34:19
Doesn't matter a whole lot.  Matter of fact, you can overtighten the top nut and adversely affect the bearings.  The nut below it, plus the fork tube bolts are doing all the work.  A top nut over it is all that's necessary.  The bottom triple is more important.  The stock R100 top triple I removed was nothing more than 4mm thick piece of plate cut into the shape of a triple.
Title: Re: Yamaha rd350 road racer
Post by: VonYinzer on Aug 05, 2016, 11:51:19
Forks are on backwards I believe ;)
Title: Re: Yamaha rd350 road racer
Post by: Hurco550 on Aug 05, 2016, 11:54:52
Forks are on backwards I believe ;)
Brakes don't go out front?
Title: Re: Yamaha rd350 road racer
Post by: VonYinzer on Aug 05, 2016, 11:57:44
 :D
Title: Re: Yamaha rd350 road racer
Post by: Hurco550 on Aug 05, 2016, 12:01:21
Ha, I just put them on like the stock Rd was. Oops.
(http://uploads.tapatalk-cdn.com/20160805/0d73cd143086e90e6661b6c16f1f7c3a.jpg)

Chances are I'll use the Rd lowers anyways. I'm only using a single rotor. That should be more than enough stop.
Title: Re: Yamaha rd350 road racer
Post by: jpmobius on Aug 05, 2016, 12:08:18
As far as I remember, 1975 and earlier had the calipers mounted in front, and later years had them behind.  Behind is much better - especially if running dual discs.  Those iron calipers are heavy!  I don't think there are any issues to swapping the assembly around, the wheel and spacers and speedo drive need to be kept as they are so the speedo will work - just the axle will have to be flipped with the forks.  Not important of course if you won't be using the speedo.
Title: Re: Yamaha rd350 road racer
Post by: Hurco550 on Aug 05, 2016, 12:09:06
Doesn't matter a whole lot.  Matter of fact, you can overtighten the top nut and adversely affect the bearings.  The nut below it, plus the fork tube bolts are doing all the work.  A top nut over it is all that's necessary.  The bottom triple is more important.  The stock R100 top triple I removed was nothing more than 4mm thick piece of plate cut into the shape of a triple.
That's kinda what I figured, the only thing that worried me was the fact that in most cases Yamaha wouldn't put a useless piece of mechanical hardware on if they didn't have to. I remember my buddies top triple on his beamer was just flat plate with bolts as you described as well.

Thanks
Title: Re: Yamaha rd350 road racer
Post by: Hurco550 on Aug 05, 2016, 12:14:47
As far as I remember, 1975 and earlier had the calipers mounted in front, and later years had them behind.  Behind is much better - especially if running dual discs.  Those iron calipers are heavy!  I don't think there are any issues to swapping the assembly around, the wheel and spacers and speedo drive need to be kept as they are so the speedo will work - just the axle will have to be flipped with the forks.  Not important of course if you won't be using the speedo.
Good to know! Planning on running a single fzr rotor with some kind of modern 2 piston caliper. Should be plenty for as light as I'm hoping this bike will end up. I was contemplating running the caliper behind anyhow. I don't know, but the extra stopping ability makes me nervous as far as pulling on the mount tabs.seems like pushing would be better, but on the same coin I've never seen any brake off. May be over thinking it, but I don't know if there is any benefit performance wise to shifting the weight of the caliper back vs. Front?

Still undecided on a speedo as well. Kinda planning on a tach only with a cell phone mount if I'm curious about my speed =p
Title: Re: Yamaha rd350 road racer
Post by: irk miller on Aug 05, 2016, 12:25:07
These are what I like to use for double pot adaptations.  I've used them on four bikes so far.  They're cheap, easy to adapt, and plentiful.  There's always a bunch on eBay without hardly a nick.  Suzuki used them on a bunch of their motorcycles...

here http://www.ebay.com/itm/2003-03-Suzuki-gsx600f-front-left-brake-caliper-oem-98-06-katana-2-piston-tokiko-/302033064893?hash=item465292d3bd:g:XN4AAOSwdj9XT7zZ&vxp=mtr (http://here http://www.ebay.com/itm/2003-03-Suzuki-gsx600f-front-left-brake-caliper-oem-98-06-katana-2-piston-tokiko-/302033064893?hash=item465292d3bd:g:XN4AAOSwdj9XT7zZ&vxp=mtr)

(http://i.ebayimg.com/images/g/xd4AAMXQstJTlhNT/s-l300.jpg)

Title: Re: Yamaha rd350 road racer
Post by: Hurco550 on Aug 05, 2016, 12:26:34
These are what I like to use for double pot adaptations.  I've used them on four bikes so far.  They're cheap, easy to adapt, and plentiful.  There's always a bunch on eBay without hardly a nick.  Suzuki used them on a bunch of their motorcycles...

here http://www.ebay.com/itm/2003-03-Suzuki-gsx600f-front-left-brake-caliper-oem-98-06-katana-2-piston-tokiko-/302033064893?hash=item465292d3bd:g:XN4AAOSwdj9XT7zZ&vxp=mtr (http://here http://www.ebay.com/itm/2003-03-Suzuki-gsx600f-front-left-brake-caliper-oem-98-06-katana-2-piston-tokiko-/302033064893?hash=item465292d3bd:g:XN4AAOSwdj9XT7zZ&vxp=mtr)

(http://i.ebayimg.com/images/g/xd4AAMXQstJTlhNT/s-l300.jpg)
Cool thanks! Link is invalid though, is that katana?
Title: Re: Yamaha rd350 road racer
Post by: jpmobius on Aug 05, 2016, 12:26:36
Question on top triple design. Planning on making my own as I don't feel like dropping $235 on this one. I've seen a few like this with the steering stem pinch bolt deleted. How crucial is it to performance/ fork flex ect to keep it intact?
It does have some value, though I can't say how much.  Clamping the top tree to the steering stem to lock it to the lower tree unquestionably stiffens up the assembly - imagine assembling just the upper and lower together and twisting the two trees against each other.  Much more rigid than just clamping down with the upper crown nut.  Most old bikes can have the whole front end twist pretty easily.  Loosen the triple tree pinch bolts and stand astride the front wheel and clamp the wheel between you knees and twist the handlebars.  Big difference when the pinch bolts are tight of course.   
Title: Re: Yamaha rd350 road racer
Post by: irk miller on Aug 05, 2016, 12:29:07
Cool thanks! Link is invalid though, is that katana?
Yeah, Katana.  They were on GS, too.  Plus a bunch of others.  Marauders, Intruders, etc.  I typically search Katana for both sides.
Title: Re: Yamaha rd350 road racer
Post by: jpmobius on Aug 05, 2016, 12:30:19
Good to know! Planning on running a single fzr rotor with some kind of modern 2 piston caliper. Should be plenty for as light as I'm hoping this bike will end up. I was contemplating running the caliper behind anyhow. I don't know, but the extra stopping ability makes me nervous as far as pulling on the mount tabs.seems like pushing would be better, but on the same coin I've never seen any brake off. May be over thinking it, but I don't know if there is any benefit performance wise to shifting the weight of the caliper back vs. Front?
In fact there is a benefit.

(from another thread)
"There is in fact a very good reason for locating the calipers behind the fork legs rather than in front.  The goal is to reduce the moment of inertia for the entire steering assembly.  More technically the polar moment of inertia, the idea is the combination of mass and distance around a point of rotation.  This is the difference you perceive between a very heavy door and a lighter one when you swing it open (or closed).  The two doors appear to be identical, but the heavy one will take more effort to get moving and likewise coast a lot further (or slam better if you like).  Alternatively, you could have a much bigger door, but if correspondingly lighter, it would seem the same as the smaller heavier door.  You can look at the front end of your bike like a door with the hinge at the steering pivot, and the width of the bars, the weight of the controls, the diameter and weight of the wheel and weight and location of the brakes etc. etc.being the weight and size of the door.
This impacts steering, though not as some might expect.  Having a super light steering assembly will indeed affect the steering, but only noticeably at parking lot speeds.  The geometry (rake and trail) is really more important for how heavy or light the steering feels at any speed.
What is very important is this:  All things have a natural frequency at which they will oscillate.  Heavy things oscillate at lower frequencies, and lighter things oscillate at higher frequencies.  Think tuning fork.  This is the ringing you hear when you drop a coin.  A similar phenomenon is present in assemblies with multiple components in motion.  The natural frequency at which your steering assembly will oscillate is determined by many things, but primarily it is a function of its mass and how that mass is distributed in relation to its axis of rotation.  You can increase the natural frequency of your steering assembly by making everything lighter, by making it more rigid, or my reducing the moment by moving weight closer to the axis of rotation.  So moving those heavy brake calipers back behind the fork legs will move them closer to the steering axis, reduce the moment of inertia and cause the natural frequency of the whole assembly to increase.  Making the wheel lighter, narrowing the bars, removing hand controls etc will have the same effect.
So why do you care about the natural frequency of your front end?  You don't unless that frequency is able to get started by your operation of the bike.  The coin in you hand does not start ringing by itself, but you can get it started by dropping it on the table.  There is rather a lot going on with the front end of your bike when rolling down the road, and if the road were perfectly smooth, the tire perfectly round and  if the rider never moved around on the bike all would be well at all speeds.  However this is not the case in real life.  Say you are traveling along at 100 mph on a smooth road and you hit a cigarette butt.  This will deflect the tire a very tiny bit.  The geometry of the steering system is inherently stable with the contact patch of the tire dragging behind the steering center generating forces that are enormous compared to the deflection so the steering returns to center and you never notice - but maybe not.  There is mass in the steering.  When the forces created by the steering geometry try to return the steering to straight, the mass wants to keep going and the assembly is deflected in the opposite direction.  This is akin to the motion of one cycle of oscillation of the natural frequency of the assembly. At low speeds, this takes place at at a rate below the assembly's natural frequency, and without another cigarette but perfectly timed to follow the first the oscillation decays out.  But as you travel faster and faster, the time it takes for this motion to be completed gets closer and closer to the natural frequency.  At some speed, that tiny deflection will match the frequency of the assembly, and every swing of the steering returning to center will be helped along by the natural frequency of the system.  The deflection you didn't even notice when you hit that cigarette will become larger and larger as long as the speed and the corresponding rate at which the geometry can return the system to neutral (straight ahead) matches the natural frequency.  The dreaded speed wobble.  Speed up, and the return to straight speed of the geometry falls out of sync with the natural frequency and the wobble goes away (of course you will have to slow down back through the danger zone eventually), or slow down for the same effect.
The world being what it is has conspired to make the typical natural frequency of a bikes front end be right in the range of typical top speeds.  So if your bike tops out at 110 mph, and the moment of inertia and stiffness of your front end make for a harmonic at 100 mph, your effective top speed is a bit less than 100 mph because it will be obviously dangerous at the frequency matching 100 mph.
Reduce the moment of inertia by moving those heavy calipers considerably closer to the steering pivot, and the natural frequency will go up noticeably.  Maybe it now takes 120 mph to match it.  Now you can cruise safely at you top speed of 110 mph because the matching harmonic speed of your front end is out of reach."
Title: Re: Yamaha rd350 road racer
Post by: Hurco550 on Aug 05, 2016, 12:37:12
Yeah, Katana.  They were on GS, too.  Plus a bunch of others.  Marauders, Intruders, etc.  I typically search Katana for both sides.
Dang, those are stupid cheap. And since you've done it I assume you don't run into many issues with spoke clearance?
Title: Re: Yamaha rd350 road racer
Post by: irk miller on Aug 05, 2016, 12:41:32
Dang, those are stupid cheap. And since you've done it I assume you don't run into many issues with spoke clearance?
Zero.  So far I've done it on a KZ front end, a GL front end, A VZ front end (dual disc conversion) and a CB750 front end.
Title: Re: Yamaha rd350 road racer
Post by: Hurco550 on Aug 08, 2016, 11:52:56
In fact there is a benefit.


Thanks for the info jp! I have read that about 3 times now, still digesting all of it. the info is appreciated!
Title: Re: Yamaha rd350 road racer
Post by: Sav0r on Aug 08, 2016, 12:24:40
I'm using the FZR caliper and rotor on my RD. It's the RD hub, but FZR forks. I'm sure the FZR caliper can be made to work with RD forks, but I bet the spacing is going to be a little tricky. The caliper is quite close to the spokes, even with the rotor spaced out.
Title: Re: Yamaha rd350 road racer
Post by: teazer on Aug 09, 2016, 02:46:03
And the same or similar are fitted to SV650 and that's what I fit on wire spoke wheel GT750s with adapters.

Double sided ( pistons pushing from both sides) are hard to fit because they hit the spokes in most cases. Stock RD calipers fit and clear the spokes but they are really heavy - 1,536gms without pads compared to say an SV650/Katana caliper at 816gms without pads according to my notes. And the disks are also very heavy on an RD at almost 3Kg each compared to say 1.300 gms on a CBR600. There are pounds to be saved right there.
Title: Re: Yamaha rd350 road racer
Post by: jpmobius on Aug 09, 2016, 09:33:05
And pounds to be saved in especially good locations!
Title: Re: Yamaha rd350 road racer
Post by: Hurco550 on Aug 09, 2016, 21:01:14
Working through making my own rearsets. Got some heim joints and aluminum round to start.
(http://uploads.tapatalk-cdn.com/20160809/fb3d925875805b59094a869cf18a1c8a.jpg)
(http://uploads.tapatalk-cdn.com/20160809/0203cad1dca896c3ad73499605003964.jpg)

I was going to go with an all joint setup similar to this.
(http://uploads.tapatalk-cdn.com/20160809/aeb5e52251fb5f3b846cd895f46dd2f7.jpg)

But I think it will be way lighter and simpler to go with a cable setup running to the rear drum. May try to use a ready made cable, like for a gt250 (and I have one handy for measuring.

Title: Re: Yamaha rd350 road racer
Post by: Hurco550 on Aug 09, 2016, 22:21:35
And the beauty of dtt, a few have been shared here. Gotta love when Google searches lead back "home".
(http://uploads.tapatalk-cdn.com/20160809/cf43e60f76ef94c7af7b66d9013b1617.jpg)
(http://uploads.tapatalk-cdn.com/20160809/933142427ff6e353c17859a5e5cd880b.jpg)
Title: Re: Yamaha rd350 road racer
Post by: irk miller on Aug 09, 2016, 22:27:45
Haha.  XB posted that Yamaha race bike on my Freeze-dried hellride CB360 thread when I was designing my rear brake setup for the clip ons on that bike. 
Title: Re: Yamaha rd350 road racer
Post by: jpmobius on Aug 09, 2016, 23:11:33
Good for you! (I like cables -though they have some issues).  Very satisfying building foot controls I think - very plain to see the mechanism, and you use it always, so you get some satisfaction of a job well done every time you ride your bike.  Take some time to understand the kinematics of the mechanism(s) and you will be well rewarded with foot controls that work really well.  If you like how the stock set up works, it is pretty easy to create new controls in a new location that work very much the same.  So keep all your original parts so you can measure them and create new controls that will give you the same function.  For example, your rear brake has a very simple pedal that operates a crank arm that pulls a rod that in turn operates another crank arm that turn a cam that pushes the rear brake shoes against the drum.  Very likely you will keep the cam and crank arm that is part of the rear brake assembly, so if you wish to keep the same "feel" of the rear brake, you simply need to keep the same ratio of brake pedal length to pedal operated crank arm in your new system and you can't go wrong.  The stock pedal is really long on an RD, but it does not matter.  It is the ratio of the pedal to the arm it operates that counts.  So if you design a shorter pedal, make the crank arm that pulls the cable correspondingly shorter.  Follow the same notion on your shifter design and your new controls will work well.

And you may ask "What issues with the cable?!!".  Cables tend to be stretchy and have "lost motion" due to convoluted routing.  The obvious solution is to 1) Make a very stout cable and housing so any "stretchy" feel is rendered unnoticeable, and 2) make the routing as close to straight as is practical.  The lost motion happens because there is considerable slack between the cable and its housing.  If you need to put a lot of force on the cable, it has to ride tightly against the housing and take up whatever slack was present before it can work with authority.  You can see that I addressed both of these issues in the pic of one of my bikes that you presented.
Title: Re: Yamaha rd350 road racer
Post by: teazer on Aug 10, 2016, 20:05:23
One we prepared earlier. 

(http://pinkpossum.com/td3/images/DSCN1724.JPG)


Drum is R5 or RD- originally a rod type.  Welded on a new cable boss and cut down the backing plate. Frame is TD3/TZ250 and cable was  GT750 Suzuki.  Much easier than all those linkages.  You could also look at a CB160 rear brake cable.

For the gearshift, use male heim joint inside aluminum tube.  It's much stiffer that 1/4" rod even if you have to bend it.  If you get fancy you could use left and right threaded heim joints but I don't have a left hand tap, so I use 2x right threads.
Title: Re: Yamaha rd350 road racer
Post by: teazer on Aug 10, 2016, 20:09:40
And the beauty of dtt, a few have been shared here. Gotta love when Google searches lead back "home".
(http://uploads.tapatalk-cdn.com/20160809/cf43e60f76ef94c7af7b66d9013b1617.jpg)

TZ or TD/TR rear brake.  Heavy as all get out but they look soooo sexy.
Title: Re: Yamaha rd350 road racer
Post by: Hurco550 on Aug 10, 2016, 20:45:56
I think I may have a solution that is looking pretty solid at the moment. I started looking closer and measuring my Suzuki gt250 cable type rear brake. Dimensionally it looks very very close to the Rd hub, and it has the lug and everything already for the cable. At one point I had another gt250 rear wheel kicking around, but I'll have to go out and dig around at my dad's place to see if it's still there. May be able to make this whole rearset deal look close to a "factory" type setup.
(http://uploads.tapatalk-cdn.com/20160810/00e838505707c988ff1598a90e71ee67.jpg)
(http://uploads.tapatalk-cdn.com/20160810/fa502525ab5c463d245fb2c68659eb9a.jpg)

Title: Re: Yamaha rd350 road racer
Post by: VonYinzer on Aug 10, 2016, 21:05:18
Neat-O
Title: Re: Yamaha rd350 road racer
Post by: Hurco550 on Aug 11, 2016, 11:42:03
Quick auto cad drawing. Mounting brackets will also have slotted slip joints for the chamber mounts, and will be made from 3/8" thick 6061 aluminum.
(http://uploads.tapatalk-cdn.com/20160811/40bcf7a118015baf531bc35033b693e7.jpg)

None of the geometry is right,  but here is an idea on the lever as well.
(http://uploads.tapatalk-cdn.com/20160811/8ac8229c6663c7f5d46e917e9765b164.jpg)

(http://uploads.tapatalk-cdn.com/20160811/51786b2cf3a84089f125e3dd83240ece.jpg)
Title: Re: Yamaha rd350 road racer
Post by: VonYinzer on Aug 11, 2016, 11:54:35
Damn you people and your fancy new fangled 'rithmatic machines.
Title: Re: Yamaha rd350 road racer
Post by: Hurco550 on Aug 11, 2016, 12:07:12
Damn you people and your fancy new fangled 'rithmatic machines.
Lol not very new, it's called draftsight, and it's basically a free version of autocad 98
Title: Re: Yamaha rd350 road racer
Post by: Hurco550 on Aug 11, 2016, 22:22:04
Well, went over to my dad's place and dug around in the haymow. I found the extra gt250 wheel. Got back to the garage and did a bunch of thorough measurement to see about doing the wheel swap. I got the Rd wheel about pulled off when I thought that I may get lucky and see if just the gt250 brake plate would fit in. Well I'll be darned it does. Almost a direct "bolt up". Same drum diameter, same axle size, same pad width the whole 9 yards. The only thing that is different is the steel bushing is a tad longer that is pressed into the plate and seats against the bearing. That can be remedied with a small spacer, otherwise it's dang near drop in.

Rd left, Suzuki right.
(http://uploads.tapatalk-cdn.com/20160811/a2e8bc71ca8a895d6749a66539522789.jpg)

Now I have a plate with the cable mount already cast in.
(http://uploads.tapatalk-cdn.com/20160811/42536e863273789ec0d59797b0f5a660.jpg)

Only other thing is the stay offset. I can bend the stock rd stay or fabricate a new one easy enough.
(http://uploads.tapatalk-cdn.com/20160811/4564acbf267a5bb475c4a93e17f49172.jpg)

I'm assuming that the hubs and brakes for some of these old Jap bikes must have been contact work or bought from a supplier as close as the design is and even dimensions. Kinda like showa forks ect.
 

Oh, doesn't look like I'll be able to re use my Yamaha pads :/
(http://uploads.tapatalk-cdn.com/20160811/2793be2b624e4fca507e9d503ce28f60.jpg)
Title: Re: Yamaha rd350 road racer
Post by: ridesolo on Aug 11, 2016, 22:39:46
Wow, great deal on that brake.  Is it luck or clean living?  Hmmm, must be luck.   ;D
Title: Re: Yamaha rd350 road racer
Post by: Hurco550 on Aug 11, 2016, 22:43:09
Since I lost some pieces when I parted it out, I'm looking for a few gt250 brake bits as well...

http://www.dotheton.com/forum/index.php?topic=71151.0
Title: Re: Yamaha rd350 road racer
Post by: Hurco550 on Aug 11, 2016, 22:51:15
Wow, great deal on that brake.  Is it luck or clean living?  Hmmm, must be luck.   ;D
Lol yeah, I'm thinking luck
Title: Re: Yamaha rd350 road racer
Post by: J-Rod10 on Aug 11, 2016, 22:58:56
Here is how I run my cable set up.
(http://i1095.photobucket.com/albums/i467/ViperBaseball14/20160228_122407_zpsnh9249b3.jpg) Simple, clean, and it works.
Title: Re: Yamaha rd350 road racer
Post by: Hurco550 on Aug 11, 2016, 22:59:56
That's really similar to how I was planning to go with it
Title: Re: Yamaha rd350 road racer
Post by: Sav0r on Aug 12, 2016, 15:09:07
Here is how I run my cable set up.
(http://i1095.photobucket.com/albums/i467/ViperBaseball14/20160228_122407_zpsnh9249b3.jpg) Simple, clean, and it works.

That's tidy!
Title: Re: Yamaha rd350 road racer
Post by: jpmobius on Aug 12, 2016, 17:02:50
Remember to keep your pedal to crank arm length ratio the same as stock if you wish to keep the same pressure and pedal travel as original.  Also, keep in mind that the crank arm can be rotated to any position to accommodate good cable routing.  Design your cable routing with as few bends as possible.  It will function much better and last much longer.  Don't design your set up to accommodate an existing off the shelf cable unless it is virtually the exact thing you want.  Design your system and then make it (or have it made) the correct length cable to fit it.  Making cables is pretty easy if you start with an existing cable like the factory Suzuki part and simply shorten it to the correct length.  This also allows you to potentially select a new cable end that might be better or easier for your design.  You should silver solder the new end to ensure its strength - it is a brake after all.  And when creating your set up be sure to set it up ideally for the suspension at normal ride height and them move the suspension through its full range of motion to make sure the cable is able to flex smoothly to any position.  There is usually a compromise between making the shortest, straightest cable/routing and having good geometry through the full range of suspension travel.  With a little care you can have both.
Title: Re: Yamaha rd350 road racer
Post by: jpmobius on Aug 12, 2016, 17:44:43
Found a couple of pics of that same brake that show a bit more of the construction.  I didn't want to weld or bolt a cable carrier to my drum backing plate (excellent job on finding the (nearly) bolt on Suzuki replacement!) so I fabricated the small arm between the axle and torque arm to hold it.  It's all aluminum and really light as it is quite small.  The cable is a stock Yamaha part on the brake end but I can't remember from what bike.  The pedal end is cutoff to the length I needed, and I think the socket fitting that holds the housing and bolts to the peg mount is also from the same original cable.  I cut the threaded section from a bolt that fits the rod end I used and bored a hole through it and silver soldered it to the cable.  Pretty simple and the cable will part before the soldered connection will give up so it is very strong.  I also made a steel bracket to mount the actual cable to mostly to make it small.  As I recall the aluminum versions I thought up were too big and chunky looking so I used steel which is likely about as heavy being very small.  The steel is also vastly more durable for wear and won't eventually fatigue like aluminum.  The stop for the pedal "up" position is fixed because I carefully located where I soldered the threaded rod to it so when the brake is not applied, the cable retracts completely into the housing and the threaded rod stops the cable from retracting any further and also seals up (sort of) the housing.  The pedal height is adjustable by adjusting how far the rod end is threaded on the the cable end.  The pedal rotates on a pair of small ball bearings pressed into the foot rest bracket.  I got tired of pedals getting sloppy after a lot of use and these are still very precise with no discernable play.  The pegs are modified off the shelf Bates folding pegs.  Abominably heavy, but the pivots and stops wear like iron (well they are!).  I really hate droopy foot pegs so I was willing to suffer the weight penalty (It is a street bike) but now a days you likely can find a slick off the shelf aluminum part.
Title: Re: Yamaha rd350 road racer
Post by: teazer on Aug 12, 2016, 18:34:54
That's a nice set up, but is that a TD/TZ swingarm I see hiding in there?
Title: Re: Yamaha rd350 road racer
Post by: jpmobius on Aug 12, 2016, 19:43:03
That's a sharp eye you have sir.  TR3 if memory serves.
Title: Re: Yamaha rd350 road racer
Post by: Hurco550 on Aug 13, 2016, 23:11:45
Thanks for all the input on rearset design! I appreciate it, and it will be implemented as I continue to design them! May end up having motion pro do up a cable for me once I have a design final.

Not much going on to speak of. I got a set of Chinese clip ons to get me going till I find the right setting, as they are fully adjustable. Once I find the sweet spot, I may make up a set out of billet permanently set to the desired angle.
(http://uploads.tapatalk-cdn.com/20160813/2b428c8714c08f2ce001ff7f95baad94.jpg)

Still trying to get this dang motor freed up. Gonna use the grease method as last ditch effort. It works good but dang it it a mess. Right now it's sitting full of my 50/50 acetone atf brew with a block heater on top.
(http://uploads.tapatalk-cdn.com/20160813/c6b1b8e578011d2d271f99fab548d02a.jpg)

Second barrel is a little trickier, as its stuck with the exhaust port open, thus won't hold fluid.
(http://uploads.tapatalk-cdn.com/20160813/a46d8f5437ead554d1a2d703659c145c.jpg)
Title: Re: Yamaha rd350 road racer
Post by: Sav0r on Aug 14, 2016, 00:15:37
I used Ox/acet, a wood block, and a hammer to get mine unstuck. It wasn't a feel good operation but I didn't damage anything either.
Title: Re: Yamaha rd350 road racer
Post by: Hurco550 on Aug 14, 2016, 00:17:37
I used Ox/acet, a wood block, and a hammer to get mine unstuck. It wasn't a feel good operation but I didn't damage anything either.
Eh, probably what I'll do, crank will likely be replaced anyways
Title: Re: Yamaha rd350 road racer
Post by: Sav0r on Aug 14, 2016, 00:29:07
I ran my crank for nearly 2k miles. It looked clean as a whistle, no rust detected, and it measured within spec, but just barely. In retrospect, I don't think I'd recommend it.
Title: Re: Yamaha rd350 road racer
Post by: Hurco550 on Aug 14, 2016, 00:31:45
I ran my crank for nearly 2k miles. It looked clean as a whistle, no rust detected, and it measured within spec, but just barely. In retrospect, I don't think I'd recommend it.
I'm really thinking I'll just buy one of those vitos drop in cranks. This one will undoubtedly need a rebuild, and for 4 builds, I can't have that done
Title: Re: Yamaha rd350 road racer
Post by: Sav0r on Aug 14, 2016, 00:36:15
I'm currently using a Vito's crank. Maybe 500 miles on it. The only opinion I have is that it's a great deal. Once I get a few more revolutions on it I will check it to see how it has held up. So far so good though.
Title: Re: Yamaha rd350 road racer
Post by: Hurco550 on Aug 14, 2016, 00:46:14
I'm currently using a Vito's crank. Maybe 500 miles on it. The only opinion I have is that it's a great deal. Once I get a few more revolutions on it I will check it to see how it has held up. So far so good though.
Good to know, I haven't found many actual reviews on them, so it's good to hear some first hand experience
Title: Re: Yamaha rd350 road racer
Post by: jpmobius on Aug 14, 2016, 13:40:36
Don't assume that just your pistons are seized in the bores.  I've seen cylinders pretty severely locked down to the case because corrosion has formed around the studs, and this definitely happens to RD's. Pour some penetrating oil into the holes for the studs and wait overnight. Then take a hammer and a block of wood and strike each cylinder alternately front and back. Be careful where you apply the blows, and don't over do it - you're just trying to get the tiniest movement. You should be able to at least get the joint at the base gasket to move no matter how badly the pistons are seized.  It may take quite a bit of fussing to get observable movement so be patient and persistent and don't over do it and break something.    As the cylinder sleeves fit quite tightly in the case, don't look for much motion - you should be able to get this joint to move a tiny bit with persistence though.  Once you do, get an assistant and while lifting the engine by one cylinder, take another block of wood and strike the top of that cylinder's piston.  Keep an eye on the base gasket joint.  Once you get it to let go you should be able to drive them off.  Under no circumstances whatever wedge anything between the case and cylinder base.
Title: Re: Yamaha rd350 road racer
Post by: advCo on Aug 14, 2016, 17:57:28
I've had good luck with a rubber mallet, striking perpendicular to the fins front and back and a bit of heat to free stuck jugs.


Sent from my iPhone using DO THE TON (https://siteowners.tapatalk.com/byo/displayAndDownloadByoApp?rid=89466)
Title: Re: Yamaha rd350 road racer
Post by: Hurco550 on Aug 14, 2016, 19:54:09
Thanks again mobius! Got the studs soaking now!

Forgot to post this about the rearsets. I am making up these arms for mockup purposes. Fully adjustable at any degree and the hole locations are every 1/4" on center. Once I get them where I want them I'll get a set cut at the right angle/ hole locations.
(http://uploads.tapatalk-cdn.com/20160814/6fbff6869902c60f57af50be900cf8ab.jpg)
(http://uploads.tapatalk-cdn.com/20160814/72ad989e411ca616862cb505d98a0f09.jpg)
Title: Re: Yamaha rd350 road racer
Post by: jpmobius on Aug 14, 2016, 23:10:50
This is a GREAT idea!  Indeed, I have done this very thing myself.  Do yourself a favor though - make the center point of all your adjustability  based on the stock kinematics.  In other words, do the simple step of measuring the stock crank arms and levers and build your trial set with these ratios as your mid point.  I expect would likely discover as I did, that you can spend a lot of time fooling around with adjustments if you just do a dart throw.  If you start with a known scheme it is much easier to make changes with a purpose.  You may also find that having the adjustability has an even more valuable use than getting the function to be good:  Having good adjustability likely will make it possible to alter the ergonomics for a much more comfortable and therefor much more functional set up.
Title: Re: Yamaha rd350 road racer
Post by: Hurco550 on Aug 17, 2016, 22:36:18
Got my rearset parts back from my waterjet guy (thanks dad! ) the actual mounts are probably, er hopefully,  permanent items, but as stated before, the levers with all the holes are just for mockup. Once I get the angles and lengths set, I'll get a set cut at a permanent angle. Also, BMX pegs are mockup only (thanks Cory) I'm really planning on trying to incorporate the stock rubber fold up pegs, and maybe try to make it look like a "factory Yamaha" type setup that you "could have gotten from the dealer" back in the day.

(http://uploads.tapatalk-cdn.com/20160817/f8751472b5bd42bcaba6a134084e4771.jpg)

(http://uploads.tapatalk-cdn.com/20160817/4a4a3dc94ca56cb63726be0376eccd60.jpg)

(http://uploads.tapatalk-cdn.com/20160817/f433f74358cedf273f6a0c63728cd60a.jpg)

(http://uploads.tapatalk-cdn.com/20160817/ac07eb5e31fd11eb363af1e71f660481.jpg)
Title: Re: Yamaha rd350 road racer
Post by: irk miller on Aug 17, 2016, 22:40:24
I like the BMX pegs.  I want something like that.  Not sure what bike, but it's a neato idea.
Title: Re: Yamaha rd350 road racer
Post by: ridesolo on Aug 17, 2016, 22:52:16
Lookin good, buddy!
Title: Re: Yamaha rd350 road racer
Post by: Hurco550 on Aug 17, 2016, 23:04:44
I like the BMX pegs.  I want something like that.  Not sure what bike, but it's a neato idea.
I like them too, I just like the idea of fold up pegs more haha cheap insurance if I get this thing a bit low once in a while lol
Lookin good, buddy!
Thanks Cory!
Title: Re: Yamaha rd350 road racer
Post by: yorkie350 on Aug 18, 2016, 06:32:51
Great idea with the rearsets turned out nice plenty of adjustment to play with and ime a +1on fold up pegs too like you say cheap insurance in the twisty bits
Title: Re: Yamaha rd350 road racer
Post by: Hurco550 on Aug 23, 2016, 17:19:03
Did a little work on some knicks that were on the front high shoulder rim.

(http://uploads.tapatalk-cdn.com/20160823/67ad58a3316a9914006e44c521af744e.jpg)
(http://uploads.tapatalk-cdn.com/20160823/bbfe0dbf288a6f0e1f33c10fc562d295.jpg)

A little dremel work too prep for welding
(http://uploads.tapatalk-cdn.com/20160823/51d64cc022ff644f2fc96115c9da9af3.jpg)

And tig welded in some matl to file back down.
(http://uploads.tapatalk-cdn.com/20160823/bd0847a4a80007191e8ed78bbb0909e5.jpg)
(http://uploads.tapatalk-cdn.com/20160823/b4063582a8a3959d8c8e7a8bc53f2461.jpg)
Title: Re: Yamaha rd350 road racer
Post by: Hurco550 on Aug 24, 2016, 15:14:25
Not perfect, but with some filing, dremel work and wet sanding, they it is fine. Not bad for a 15 dollar high shoulder rim and some elbow grease.
(http://uploads.tapatalk-cdn.com/20160824/1e06ececc3e2d4cd9b46368c12e756f2.jpg)
Title: Re: Yamaha rd350 road racer
Post by: JustinLonghorn on Aug 25, 2016, 07:13:48
Neat-o
Title: Re: Yamaha rd350 road racer
Post by: Hurco550 on Aug 29, 2016, 19:43:10
Kinda in a lull on this one. I've been trying to sell anything I can to raise money for this thing so I can buy some parts and keep this rolling.

New crank (or rebuild) is a must, pretty much set on a new drop in unit from vito

Pisons and bore, planning on running pro x modified banshee.

Gonna buy a used set of banshee manifolds with a cross over tube. Having a hard time finding specs if my stock carbs will be the same size though.

Y boot with k&n filter

And, I opened up my stator cover to see this
(http://uploads.tapatalk-cdn.com/20160829/a187100f6831fa7d642949e10a68153d.jpg)
Super crusty.

Really contemplating buying this and being done with it instead if trying to piece together a whole different used system. Any of you guys familiar with this system or are currently running it?

https://www.economycycle.com/shop/yamaha-rd250350400r5ds6ds7-parts/mzb-cdi-electronic-igntion-for-yamaha-rd250350400r5ds7-street-version/
Title: Re: Yamaha rd350 road racer
Post by: teazer on Aug 29, 2016, 20:18:27
Oh dear.  That's a bit crusty, to be polite.

Good crank with all new seals is a must have and I like your choice of pistons and carbs. 

I made the silly mistake of looking at a Banshee motor to drop into an RD frame for drag racing and that took me to 421 cub kits and long stroke cranks and Oh My that stuff is not cheap.  Nice to look at and dream about but spendy.  The Vito's cranks are remarkably cost effective compared to rebuilding an old crank, after you factor in new rod kits and bearings plus assembly labor and you still have an old crank that may have been revved too hard.  That said, I have never bought a NEW crank.  I have had a few rebuilt over the years by different people.  before you buy a crank, call around and see what the cost would be to get a professional crank rebuild from a specialist shop.
Title: Re: Yamaha rd350 road racer
Post by: Hurco550 on Aug 29, 2016, 20:31:52
Oh dear.  That's a bit crusty, to be polite.

Good crank with all new seals is a must have and I like your choice of pistons and carbs. 

I made the silly mistake of looking at a Banshee motor to drop into an RD frame for drag racing and that took me to 421 cub kits and long stroke cranks and Oh My that stuff is not cheap.  Nice to look at and dream about but spendy.  The Vito's cranks are remarkably cost effective compared to rebuilding an old crank, after you factor in new rod kits and bearings plus assembly labor and you still have an old crank that may have been revved too hard.  That said, I have never bought a NEW crank.  I have had a few rebuilt over the years by different people.  before you buy a crank, call around and see what the cost would be to get a professional crank rebuild from a specialist shop.

bill bune is $150 labor + parts for rebuild and true
economy cycle is $580 with parts besides center labyrinth seal (which mine may very well need)
My local guy (mototech usa) is about $130 for labor plus parts
even my local guy at $130 would only leave $270 for parts (comparing it to the $400 vitos unit), which would be cutting it close for new bearings, seals and conrods I would think.

also will stock rd carbs fit into stock banshee manifold?
Title: Re: Yamaha rd350 road racer
Post by: teazer on Aug 29, 2016, 20:34:23
Lab seals rarely wear out.

Yes on the manifolds.  I used them on a couple of RD projects years ago. Jetting may change slightly in the midrange IIRC but pipes and filters will have more impact that the balance tube.
Title: Re: Yamaha rd350 road racer
Post by: Hurco550 on Aug 29, 2016, 20:40:12
Lab seals rarely wear out.

Yes on the manifolds.  I used them on a couple of RD projects years ago. Jetting may change slightly in the midrange IIRC but pipes and filters will have more impact that the balance tube.

honestly not super familiar with lab seals, but ive heard that they rarely go bad. I am just concerned about the overall shape of the crank. pretty sure that there had been water in the crank, and the whole thing may be crusty. ill find out once I finally get this top end apart and get the cases split.

Thanks for the info on the banshee boots!
Title: Re: Yamaha rd350 road racer
Post by: clem on Aug 29, 2016, 22:54:00
Hey man I've got the MZB on my DS7. It was an easy install, the wiring is not that hard to figure out. I have run without the battery as well. PM me if you need any help, I hate typing after work hours.
I also ordered some .75mm over prox banshee pistons Friday to find out that they are back ordered everywhere. They should come available mid September.

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Title: Re: Yamaha rd350 road racer
Post by: Hurco550 on Aug 29, 2016, 23:34:45


Hey man I've got the MZB on my DS7. It was an easy install, the wiring is not that hard to figure out. I have run without the battery as well. PM me if you need any help, I hate typing after work hours.
I also ordered some .75mm over prox banshee pistons Friday to find out that they are back ordered everywhere. They should come available mid September.

Sent from my SAMSUNG-SM-G920A using DO THE TON mobile app (http://'https://siteowners.tapatalk.com/byo/displayAndDownloadByoApp?rid=89466')

Thanks man, Will probably take you up on that. My two weakest points are electrical and paint, and since this isn't getting a paint job per say (leaving the fairing as is) that just leaves electrical as my biggest pain at this point. I'm really planning super minimalist on the electrical on this, headlight tail/ brake lights and turn signals with a kill switch and hoping no battery. Definitely no dummy lights or any of that.

I am still a little ways away from ordering pistons so hopefully it won't be bad when it gets to that point, and my jugs are stock bore, so .25 over should do it hopefully. I think there are a few sets of those on feebay right now
Title: Re: Yamaha rd350 road racer
Post by: jpmobius on Aug 29, 2016, 23:36:00
I like the MZB as well (making an assumption - link seems not to work for me).  Can verify the Rz manifolds to work fine but have not seen distinct benefit with the cross over tube.  Certainly no downside in my experience though.  I like the pro-x banshee pistons too.  MZB is great for no battery.  I really like the OEM Banshee set up for ignition but it requires a custom crank - not bad if you are building new already.  Super reliable.  Check with your machinist before ordering pistons.  If you do only one modification, re-machine the heads and cylinder tops and use o-rings instead of the copper gaskets.
Title: Re: Yamaha rd350 road racer
Post by: teazer on Aug 30, 2016, 01:21:13
try this:  https://www.economycycle.com/shop/yamaha-rd250350400r5ds6ds7-parts/mzb-cdi-electronic-igntion-for-yamaha-rd250350400r5ds7-street-version/

Title: Re: Yamaha rd350 road racer
Post by: Hurco550 on Aug 30, 2016, 01:31:22
try this:  https://www.economycycle.com/shop/yamaha-rd250350400r5ds6ds7-parts/mzb-cdi-electronic-igntion-for-yamaha-rd250350400r5ds7-street-version/
For some reason, tapatalk doesn't like to open that link, but a regular browser (chrome in my case) will
Title: Re: Yamaha rd350 road racer
Post by: Hurco550 on Aug 30, 2016, 13:49:12
Been doing some reading on gasket matching. Any of you guys done it? Is it worth doing? Any real benefits seen from it on rd's?
Title: Re: Yamaha rd350 road racer
Post by: jpmobius on Aug 30, 2016, 16:11:52
I always do, but on the stock parts (I assume you are talking about the upper case to cylinder match) it doesn't matter so much.  If you place the base gasket on the cylinder you will see quite a mismatch, but when you place it on the case you will see it matters much less or not at all.  If you bolt up the empty top case to the cylinders and match up and/or alter the transfer ports then the stock base gaskets will stick out quite a bit into the transfers but if all the parts are stock then in most cases it won't matter due to the factory mismatch.  It is REALLY important that the base gasket surface on the two parts is really flat and unmarked.  If some hack has got in there with a screwdriver or chisel to pry the cylinder up (I've seen this a fair bit on RD's) you can have a lot of trouble.  RD's have very little real estate to seal the cylinder base, and even a tiny bit of damage can cause a leak.  Air leaking into the transfers can be quite terminal and very hard to discover if between the cylinders.  If you suspect trouble, machine the parts flat and use a thicker base gasket to make up for the difference.  As far as the port matching benefits in general goes, every little bit helps, but as a single item I think it a pretty small gain (of course this depends rather a lot on how bad the mismatch is and where).  It is however free, and very little trouble to do so why wouldn't you?  If you already have your bottom end together, I would match the gaskets to the cylinders and carry on.
Title: Re: Yamaha rd350 road racer
Post by: Hurco550 on Aug 30, 2016, 18:37:43
thanks Mobius!

I will have the engine apart soon and will have a look then to see how bad the match is. I think I was looking at it the same way you are, it wont cost me anything to do myself, so why not take that extra edge if its there to be had?

Talked to my local rd buddy. He is a young guy in the world of 2 strokes (25 or so id guess) but was brought up in the world of roadracing. His grandpa and great uncle were road racers in the glory days, and I still frequent his grandpas salvage yard, which is also where I got this project from. Here are a few pictures of it, just to make your mouth water =) They said I can post pics, but they don't want me to post pics and say where its at, they are a little finicky about not wanting the world to know. BTW these pics don't show the building/ outside where the other +- 700 bikes are =P

(http://uploads.tapatalk-cdn.com/20160830/ab5672c617b06e045b9d986c7db23847.jpg)

(http://uploads.tapatalk-cdn.com/20160830/ea0a12e985c18b3d23edba33bef405c3.jpg)

(http://uploads.tapatalk-cdn.com/20160830/6c3a81c0e48efefae0a118bdf11f0558.jpg)

(http://uploads.tapatalk-cdn.com/20160830/9d7f298e0347687a9f77085499b14a93.jpg)


all that to say, I was quizzing the kid about what carbs he has on his rd (rd250 with a 350 top end, tuned with chambers). He has 34 mm mikuni flat slides on them, but cautioned me that those will likely be overboard for my goad with this bike and said 32 max is what he recommended.

At the same time, he recommended BORING my stock 28's out to 30 and rejet. YES, bore them. Have any of you guys ever done this or tried it? I am a machinist and im not afraid to give it a shot, but I was wondering if its something you have done before successfully?

Side note: looking for a stock set of reed cages for the bike, ones I have are CRUSTY!
Title: Re: Yamaha rd350 road racer
Post by: jpmobius on Aug 30, 2016, 19:36:25
Sorry to report that I have NOT bored out the 28s, but do recall that being reported to be a proven good plan.  Can't recall from what source though.  I do have a pretty heavily altered 350 with 34s on it and it runs very well, so you can get them to work well on a street bike.  I wouldn't claim that it is actually faster than with 30s on it though.  Back when I put it together I had run the almost same engine with 30mm Lectron carbs and it seemed to run about as good.  That is all just opinion - no evidence just riding impressions.  For what its worth, the bike with the 34 Mikuni carbs (old style VMs, not flat slides) has very wide ports but comparatively mild port timing so it has pretty smooth power below the jump to hyperspace.  The big carbs do seem to do well at high revs - the pipes are old Factory Pipe Products and it likes to run off the end of the tach which is very hard on cranks and the wide ports are pretty hard on the rings so consequently I take it pretty easy on it the rare times I drive it.  It's great fun for 20 or 30 minutes and then it is sort of a bit much for a street bike.  Only mentioning that because I have found it pretty easy to make your bike less fun over all even though it goes faster.  I have an absolutely bone stock '74 Rd that I drive most of the time.  It is very noticeably heavier and slower, but being a bit more balanced it is much easier and after a long day more fun.  And while it may seem like no big deal, the bike with the 34s drinks an absolutely incredible volume of gasoline.  If you think you put a lot in your stock bike, you'll be in for a shock with big carbs!
Title: Re: Yamaha rd350 road racer
Post by: Hurco550 on Aug 30, 2016, 20:17:51
Sorry to report that I have NOT bored out the 28s, but do recall that being reported to be a proven good plan.  Can't recall from what source though.  I do have a pretty heavily altered 350 with 34s on it and it runs very well, so you can get them to work well on a street bike.  I wouldn't claim that it is actually faster than with 30s on it though.  Back when I put it together I had run the almost same engine with 30mm Lectron carbs and it seemed to run about as good.  That is all just opinion - no evidence just riding impressions.  For what its worth, the bike with the 34 Mikuni carbs (old style VMs, not flat slides) has very wide ports but comparatively mild port timing so it has pretty smooth power below the jump to hyperspace.  The big carbs do seem to do well at high revs - the pipes are old Factory Pipe Products and it likes to run off the end of the tach which is very hard on cranks and the wide ports are pretty hard on the rings so consequently I take it pretty easy on it the rare times I drive it.  It's great fun for 20 or 30 minutes and then it is sort of a bit much for a street bike.  Only mentioning that because I have found it pretty easy to make your bike less fun over all even though it goes faster.  I have an absolutely bone stock '74 Rd that I drive most of the time.  It is very noticeably heavier and slower, but being a bit more balanced it is much easier and after a long day more fun.  And while it may seem like no big deal, the bike with the 34s drinks an absolutely incredible volume of gasoline.  If you think you put a lot in your stock bike, you'll be in for a shock with big carbs!

I think I may give it a shot, even if just for the heck of it. I guess its another one of those "free upgrade" things if it doesn't seem to be absolutely bonkers to you. Worse case, im out a set of stock carbs. I also have a pile of Various Mikunis off of snowmobiles that I could tinker with, but I don't know if that's a road I wanna go down, mostly because about every one of them will need a rebuild (at least bowl gaskets and float valves) and you start getting into a whole different headache when it comes to that.
The other nice idea to me about boring the 28's out to 30's is that im still stock rd. No need to mess with different or custom cables (besides shorter main throttle cable for the clip ons) and stock (or stock banshee) manifolds and all that jazz..
Title: Re: Yamaha rd350 road racer
Post by: clem on Aug 30, 2016, 21:19:56
I know this isn't as wild but I have 28's on my DS7 that came with 26's. With the larger carbs it is very jet sensitive but we do have pretty good temp and humidity swings down here. I am actually looking for to putting the cylinders on that go with the carbs so hopefully I can put that to bed. It gets old rejetting so often.

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Title: Re: Yamaha rd350 road racer
Post by: Hurco550 on Aug 30, 2016, 21:27:00
I know this isn't as wild but I have 28's on my DS7 that came with 26's. With the larger carbs it is very jet sensitive but we do have pretty good temp and humidity swings down here. I am actually looking for to putting the cylinders on that go with the carbs so hopefully I can put that to bed. It gets old rejetting so often.

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Shot in the dark, but could some of that sensitivity be due to the piston port vs the reed motor of an rd?
Title: Re: Yamaha rd350 road racer
Post by: clem on Aug 31, 2016, 11:27:53
Well, I guess that it could being that it inherently runs rich down low. Check out Klemmvintage.com he has a few good writeups that cover tuning and carbs. He also covers how the intake signal from the crankcase volume is weakened with larger bore carbs.

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Title: Re: Yamaha rd350 road racer
Post by: teazer on Aug 31, 2016, 12:18:55
IIRC 28s can be offset bored to 29.5 but take nothing off the floor of the carb and remember that the slide is nominally 30.0mm so if the boring is even slightly off center left to right, the slide will not shut off air supply.

Remember also that an RZ350 will make 60+ RWHP with 26mm carbs, so they are not the limiting factor here.

A.G.Bell had a set of dyno runs in his book on 2 stroke tuning with an RD400 running stock carbs compared to 34s and if I remember, the 28s were better at almost all useful revs.

I use 34 or 36s on a TZ350 but it has nothing below about 8,000 revs.  For a race bike go with large carbs, on thr street keep costs and hassles down with stock 28s. Larger carbs have to opened up very slowly to avoid that big empty waaaaaagh sound as it falls flat on its face.  If the throttle is opened too fast/far gas velocity drops precipitously and no fuel is pulled out of the float bowl.  Bigger carbs tend to be more jet sensitive as a result.   
Title: Re: Yamaha rd350 road racer
Post by: Sav0r on Aug 31, 2016, 13:33:04
I run TM28's on my RD. Pulls like a tractor down low (it's almost too grunty at times), wheelies like an RD at the power band, and continues on pulling right to around 9,500 where it goes flat pretty hard. The ID on my stingers is a little on the small side and kills me up high. I plan to make some new silencers internals soon to fix that. But a couple of times I ran without the silencers and 10k was no issue at all. The 28's are also super easy to tune. Very responsive to changes. Lot's of people told me I should have gone for 30's or 32's, but I'm glad I went with 28's. They work very well.
Title: Re: Yamaha rd350 road racer
Post by: irk miller on Aug 31, 2016, 14:25:48
I prefer low end torque for street, personally.  I like SavOr's suggestion on the TM28.  Or what about a pumper carb? 
Title: Re: Yamaha rd350 road racer
Post by: jpmobius on Aug 31, 2016, 14:41:04
Larger carbs have to opened up very slowly to avoid that big empty waaaaaagh sound as it falls flat on its face. 

Right!  Forgot all about that for some reason. Guess I must have adapted without realizing it!
Title: Re: Yamaha rd350 road racer
Post by: Sav0r on Aug 31, 2016, 15:11:19
I was actually planning to adapt pumper carbs to my RD but got too good of a deal on the TM28's to pass up ($120 for two unused carbs and a throttle cable). I have 5 billet pumper carbs similar to non-anodized carb pictured below. They however are only 24mm bores so they are perhaps a little small. I had a line on two Ibea 29mm flat slide pumper carbs but they were a little pricey at $350 a piece (used). I figured they would be the bee's knees, but I figured paying rent was more important than street bike carburetors.

(http://www.vamec.it/assets/images/catalog/products/small/C033.jpg)

(http://images.forum-auto.com/mesimages/577364/ibea-slide-carb.JPG1..jpg)
Title: Re: Yamaha rd350 road racer
Post by: Hurco550 on Aug 31, 2016, 20:20:09
IIRC 28s can be offset bored to 29.5 but take nothing off the floor of the carb and remember that the slide is nominally 30.0mm so if the boring is even slightly off center left to right, the slide will not shut off air supply.

Remember also that an RZ350 will make 60+ RWHP with 26mm carbs, so they are not the limiting factor here.

A.G.Bell had a set of dyno runs in his book on 2 stroke tuning with an RD400 running stock carbs compared to 34s and if I remember, the 28s were better at almost all useful revs.

I use 34 or 36s on a TZ350 but it has nothing below about 8,000 revs.  For a race bike go with large carbs, on thr street keep costs and hassles down with stock 28s. Larger carbs have to opened up very slowly to avoid that big empty waaaaaagh sound as it falls flat on its face.  If the throttle is opened too fast/far gas velocity drops precipitously and no fuel is pulled out of the float bowl.  Bigger carbs tend to be more jet sensitive as a result.

I run TM28's on my RD. Pulls like a tractor down low (it's almost too grunty at times), wheelies like an RD at the power band, and continues on pulling right to around 9,500 where it goes flat pretty hard. The ID on my stingers is a little on the small side and kills me up high. I plan to make some new silencers internals soon to fix that. But a couple of times I ran without the silencers and 10k was no issue at all. The 28's are also super easy to tune. Very responsive to changes. Lot's of people told me I should have gone for 30's or 32's, but I'm glad I went with 28's. They work very well.

well that's good to know. once again thanks guys. I will plan on sticking with the stock 28's for now and once I get it together, if there is a need, I will bore or go up a size on carbs. with the whole "roadracer" vibe, I still forget that this is going to be a sheep in wolves clothing so to speak. Look of a race bike, yet still streetable.
Title: Re: Yamaha rd350 road racer
Post by: Hurco550 on Aug 31, 2016, 20:25:18
also, dumb question im sure, but does the k&n y boot mod still use a stock rd y boot, and you just clamp a k&n filter to it?
Title: Re: Yamaha rd350 road racer
Post by: Hurco550 on Aug 31, 2016, 22:05:28
Something non engine related. Been wanting to build an alloy tank for a while, but I'm not much of a sheet metal guy. Saw a video on what a guy calls "flow forming" and decided to give it a shot. I got on the old south bend and started making the tooling.

(http://uploads.tapatalk-cdn.com/20160901/744e878ee73bdb83e2f6bf8858ca1ece.jpg)

(http://uploads.tapatalk-cdn.com/20160901/d8ffa5d62c1cb5e23cb44648e75103ad.jpg)

(http://uploads.tapatalk-cdn.com/20160901/1aef9b8cc7aa30c490b9bf5c7785e1c6.jpg)

(http://uploads.tapatalk-cdn.com/20160901/b4a50929e5b2ff444671114198df2e68.jpg)

(http://uploads.tapatalk-cdn.com/20160901/486c340f135bc1550d628aec6c4749bf.jpg)

(http://uploads.tapatalk-cdn.com/20160901/eafe46ba2f1c2d78042e4a6fb6ae67d3.jpg)

Basic idea would be to make the profile of the top of my tank in a piece of hardwood and start forming, but for a test I just used a piece of pipe. Turned out ok on 16 gauge steel.
(http://uploads.tapatalk-cdn.com/20160901/2573670b4f0c071c08f428012c72d044.jpg)

(http://uploads.tapatalk-cdn.com/20160901/77c5e4692c75b23aae95d81dd9af6270.jpg)
Title: Re: Yamaha rd350 road racer
Post by: JustinLonghorn on Sep 01, 2016, 08:35:29
That is a very interesting way of shaping metal. Keep it up, man.
Title: Re: Yamaha rd350 road racer
Post by: jpmobius on Sep 01, 2016, 11:36:51
You can use the stock Y boot but the filter does not directly attach to it.  You will need a short internal coupler to go inside both and two clamps.  This is very easy to make as the most common size of canned beans, vegetables, etc is the exact diameter needed.  Simply cut the length coupler needed and install!  I use K&N part #RC-2600.  That has the same base as Y-boot but the filter section is tapered.  Fits a lot better on RD's than the straight section ones.  You can see the coupler in first pic and how the filter fits in the second.

Title: Re: Yamaha rd350 road racer
Post by: Hurco550 on Sep 01, 2016, 15:12:50
Thanks moby! Anything sporting the weight of the filter or is it just hanging on the boot?
Title: Re: Yamaha rd350 road racer
Post by: jpmobius on Sep 01, 2016, 16:20:02
Nothing supports it, it is just cantilevered out from the carbs, which are themselves completely unsupported cantilevering out from the cyilnders.  Does not seem to be a problem, but their is a frame cross brace directly under the boot and it is very close so if ever there was any sagging the boot would almost immediately rest on it.  Does not seem to be an issue even after a long time though as I don't see the boots ever actually ending up resting on the frame.
Title: Re: Yamaha rd350 road racer
Post by: Hurco550 on Sep 02, 2016, 01:25:33
Well, flow forming tool 1.0 already went out, very dishonorably at that. For the shank I just used a habbah freight chisel cut down. I knew it was high carbon steel and would probably crack. I hoped it wouldn't, but it did.
(http://uploads.tapatalk-cdn.com/20160902/1f42797277569a1b1d2cb129bbc0fd7e.jpg)

So, I figured I'd start whittling away at a billet chunk of mystery steel that I snagged out of a scrap hopper. Guessing it's 1018 crs or similar, so I don't know how long it will hold up to the air chisel. May have to end up tig welding some hard face rod on the tip where it goes in the hammer, but we shall see.

Started out with a 1.125 " x  6" chunk
(http://uploads.tapatalk-cdn.com/20160902/78c9bbcd742b2e25610dc615cd770acd.jpg)

And started making chips
(http://uploads.tapatalk-cdn.com/20160902/b764595049040283546ec877c6316a94.jpg)

(http://uploads.tapatalk-cdn.com/20160902/d37f01c935a4939a337ff97bab968ad8.jpg)

1st op done, time to flip it around (my 3 jaw Chuck has seen better days, so I'm getting pretty quick at indicating in a 4 jaw Chuck ha
(http://uploads.tapatalk-cdn.com/20160902/881fe63eb86830ed04b4bdcfb03bac29.jpg)

More turning
(http://uploads.tapatalk-cdn.com/20160902/eb48a8a4915cd41e7d06274f542d20e6.jpg)

Finished up besides turning the tube to be welded on the end that holds the wood insert. I'm really pretty impressed with the 1937 south bend. Still held a half thou tolerance on the od at 4" length of cut. Can't complain about that.

(http://uploads.tapatalk-cdn.com/20160902/8673e0370774315708f65bb2e21d9db3.jpg)

(http://uploads.tapatalk-cdn.com/20160902/b6ced6250234495dd417e5380fc7ef92.jpg)
Title: Re: Yamaha rd350 road racer
Post by: advCo on Sep 02, 2016, 02:54:06
That is pretty nifty. You machinists, you. Is that nylon at the tip?


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Title: Re: Yamaha rd350 road racer
Post by: Hurco550 on Sep 02, 2016, 22:50:41
That is pretty nifty. You machinists, you. Is that nylon at the tip?


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Most guys use some type of hard plastic like uhmw or delrin. I used a piece of hardwood dowel rod, cuz that's all I had ha
Title: Re: Yamaha rd350 road racer
Post by: Hurco550 on Sep 02, 2016, 22:54:05
Got my banshee manifold in with the crossover tube. Baby steps lol
(http://uploads.tapatalk-cdn.com/20160903/fc0c4eb108628848c0500cfb8575d8a8.jpg)
Title: Re: Yamaha rd350 road racer
Post by: Hurco550 on Sep 02, 2016, 22:56:43
What's the consensus on running the banshee manifold with stock reeds? Just trim these little ears off?(http://uploads.tapatalk-cdn.com/20160903/6f0ffae79532fd561b03d2ffbafbc33c.jpg)
Title: Re: Yamaha rd350 road racer
Post by: Ply318ci on Sep 02, 2016, 23:50:35
Yep.


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Title: Re: Yamaha rd350 road racer
Post by: Shoeman on Sep 03, 2016, 09:57:21
Leave the ears.  They help smooth the airflow into the cage.  Steps cause turbulence. 
Title: Re: Yamaha rd350 road racer
Post by: Tune-A-Fishİ on Sep 03, 2016, 10:39:56
Leave em... get a set of V-Force reeds for a banshee mang... It's only $$$$$$  :o
Title: Re: Yamaha rd350 road racer
Post by: Hurco550 on Sep 03, 2016, 10:44:55
Leave the ears.  They help smooth the airflow into the cage.  Steps cause turbulence.
They don't fit in the cage
Title: Re: Yamaha rd350 road racer
Post by: Ply318ci on Sep 03, 2016, 10:55:07
I had to cut them off on my RD to make them fit.


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Title: Re: Yamaha rd350 road racer
Post by: Shoeman on Sep 03, 2016, 11:01:03
Oops.  I did not realize you were still using stock RD cages.  Definitely not going to fit.  Off they go then. 
Title: Re: Yamaha rd350 road racer
Post by: Shoeman on Sep 03, 2016, 11:13:39
So you just wanted those manifolds for the crossover tube to maybe add a boost bottle later?   Fair enough.   Related story from my racing days, I once saw a fellow RD racer blow a piston to smithereens like ya do once in awhile, and it not only smashed the reed cage to bits but it also let the other still running non-exploded cylinder suck all kinds of tiny fragments through the bottle and wreck the piston and head on that side too.  It was impressive.   A rare occurrence though, and one you're not likely to run into.   It took him quite a bit of work during the rebuild to make sure he got all the debris out of the bottle as well.  In fact now that I think about it (20 years ago mind you) he ditched the bottle and went back to standard manifolds.  Got paranoid about it happening again.   
Title: Re: Yamaha rd350 road racer
Post by: Hurco550 on Sep 03, 2016, 17:33:50


So you just wanted those manifolds for the crossover tube to maybe add a boost bottle later?   Fair enough.   Related story from my racing days, I once saw a fellow RD racer blow a piston to smithereens like ya do once in awhile, and it not only smashed the reed cage to bits but it also let the other still running non-exploded cylinder suck all kinds of tiny fragments through the bottle and wreck the piston and head on that side too.  It was impressive.   A rare occurrence though, and one you're not likely to run into.   It took him quite a bit of work during the rebuild to make sure he got all the debris out of the bottle as well.  In fact now that I think about it (20 years ago mind you) he ditched the bottle and went back to standard manifolds.  Got paranoid about it happening again.   

Yeah, probably just stick with the crossover tube for now. A Few people recommended it. Funny, I got my love of vintage two stroke bikes from growing up working on and riding vintage sleds. Many of them have a 2 into 1 exhaust with a shared chamber, and I've seen em puke part of a piston out of one cylinder onto the manifold only to be sucked into the other side, thoroughly destroying it too lol
Title: Re: Yamaha rd350 road racer
Post by: redwillissuperman on Sep 06, 2016, 00:46:41
So you just wanted those manifolds for the crossover tube to maybe add a boost bottle later?   Fair enough.   Related story from my racing days, I once saw a fellow RD racer blow a piston to smithereens like ya do once in awhile, and it not only smashed the reed cage to bits but it also let the other still running non-exploded cylinder suck all kinds of tiny fragments through the bottle and wreck the piston and head on that side too.  It was impressive.   A rare occurrence though, and one you're not likely to run into.   It took him quite a bit of work during the rebuild to make sure he got all the debris out of the bottle as well.  In fact now that I think about it (20 years ago mind you) he ditched the bottle and went back to standard manifolds.  Got paranoid about it happening again.   
Pro Tip: if you ever grenade one cylinder, on anything, you need to rebuild all cylinders since whatever "trick" you employed on that one, is going to eat all the others.

Nice built otherwise. I would suggest you decide and do the cylinder port work and exhaust before deciding on manifolds and cages.
Title: Re: Yamaha rd350 road racer
Post by: Hurco550 on Sep 06, 2016, 15:04:19
Made a little headway the last few days. Made some fixturing to deck the jugs and put the o ring groove in.

(http://uploads.tapatalk-cdn.com/20160906/e2c377772c03df256e3bc1081c368382.jpg)

(http://uploads.tapatalk-cdn.com/20160906/820f5941532cc7d194409942e24622e7.jpg)

(http://uploads.tapatalk-cdn.com/20160906/3cf209144c0fcf5b1adfa15cc045e72a.jpg)

(http://uploads.tapatalk-cdn.com/20160906/611f1e756e34c9e19fce1b30e7dbba4a.jpg)

Plate goes into the transfer ports to draw it to the fixture.
(http://uploads.tapatalk-cdn.com/20160906/69c2d809125fac97fe224c97dd42a74d.jpg)

Aluminum block makes sure the all thread stud doesn't walk size to side allowing the hold down to exit the ports
(http://uploads.tapatalk-cdn.com/20160906/5acec2aa7966b25020373aa2d877176b.jpg)

All thread goes clear through the spindle holding it all together
(http://uploads.tapatalk-cdn.com/20160906/d74913a0860d15def6e30dd9273e3067.jpg)

Setup and took a light skim on the bottom of the sleeve (about .002") to assure that it seats parallel when I turn it around to shave the deck.
(http://uploads.tapatalk-cdn.com/20160906/2111e2cdbde24f4128d1310ab41bd24e.jpg)

Flipped around and checked it with a dial indicator. Within a thou ask around. Btw this is just an extra r5 barrel I have to setup.
(http://uploads.tapatalk-cdn.com/20160906/1cfe237899828b6cb03acc90a638a09f.jpg)
(http://uploads.tapatalk-cdn.com/20160906/7ddb76387d2b41ff8175cb62d84f5d9e.jpg)
Title: Re: Yamaha rd350 road racer
Post by: jpmobius on Sep 06, 2016, 15:20:31
Looks like the right thing!  You might be money ahead to face off the base gasket surface while your at it. Obviously you'll have to machine the squish and chambers for the new deck height so there is no downside.  If you match up the transfers there is pretty spare sealing surface and knowing the base is true is cheap insurance.  Of course the case needs to be flat as well, but while you're there on the cylinders. . .
Title: Re: Yamaha rd350 road racer
Post by: Hurco550 on Sep 06, 2016, 18:28:20
Looks like the right thing!  You might be money ahead to face off the base gasket surface while your at it. Obviously you'll have to machine the squish and chambers for the new deck height so there is no downside.  If you match up the transfers there is pretty spare sealing surface and knowing the base is true is cheap insurance.  Of course the case needs to be flat as well, but while you're there on the cylinders. . .

Thanks! I was planning on doing that actually. should be able to get away with only taking a few thou, which is a low price to pay for a nice gasket surface. ill have to see what shape the cases are in, but im pretty sure im the first one to have this motor apart(or at least the barrels are at stock bore), so hopefully not to bad
Title: Re: Yamaha rd350 road racer
Post by: Hurco550 on Sep 08, 2016, 04:42:23
Finally got one barrel off the bike and on the lathe. Have another set of jugs and heads, so this was a "practice", but will be nice to have a second top end around.

Skimmed about .002" off the bottom of the skirt to true it for the other end operation, as well as .002" off for a gasket surface clean up.

Before
(http://uploads.tapatalk-cdn.com/20160908/b4eb2c5aee6ba55167320499a2e8566d.jpg)

After(http://uploads.tapatalk-cdn.com/20160908/e102e591b9c3b19118d32c695861d288.jpg)

Flipped and indicated. Turned off the gasket step and took about .002" off the gasket surface to clean it up as well

Before
(http://uploads.tapatalk-cdn.com/20160908/9427cbb087260e99246abef084da0e7b.jpg)

After(http://uploads.tapatalk-cdn.com/20160908/363c1229111e0372d2a9c4d7bb8dea47.jpg)

Ground a hss bit for the o ring groove
(http://uploads.tapatalk-cdn.com/20160908/c8003e9974627a2ef446c1a5fd59373d.jpg)

Cut the groove in to tz350 o ring groove dimensions (thanks teazer!!)
(http://uploads.tapatalk-cdn.com/20160908/d055c711ddfa06fbea9e349fecbc4644.jpg)

Now just a few more to go.
(http://uploads.tapatalk-cdn.com/20160908/757a19fd4dc1f9a30ccf1f5761110da3.jpg)
Title: Re: Yamaha rd350 road racer
Post by: Sav0r on Sep 08, 2016, 10:13:38
Looks really good! I wish I had a junk cylinder to experiment on. I'd like to try to o-ring a set on my mill.
Title: Re: Yamaha rd350 road racer
Post by: jpmobius on Sep 08, 2016, 10:42:59
Looks great!  Alignment of the heads on the cylinders is very sloppy on RD's so on the 350 cylinders it is good to leave a step and cut a mating step into the heads when you do the work on them.  That way the head will be perfectly centered on the cylinder and you can set the squish very accurately.  Of course you can achieve the same thing with dowels or pins, but it is then more difficult to have interchangeable heads.  Spark plug location can be a bit off also so it is a good idea to face off the top of the hole assuming your going to make a fixture to turn the heads as well.
Title: Re: Yamaha rd350 road racer
Post by: Hurco550 on Sep 08, 2016, 11:02:21
Looks really good! I wish I had a junk cylinder to experiment on. I'd like to try to o-ring a set on my mill.
Thanks! Wouldn't call it a junk set, just a slightly sweaty extra. Still usable, just extra
Looks great!  Alignment of the heads on the cylinders is very sloppy on RD's so on the 350 cylinders it is good to leave a step and cut a mating step into the heads when you do the work on them.  That way the head will be perfectly centered on the cylinder and you can set the squish very accurately.  Of course you can achieve the same thing with dowels or pins, but it is then more difficult to have interchangeable heads.  Spark plug location can be a bit off also so it is a good idea to face off the top of the hole assuming your going to make a fixture to turn the heads as well.
Thanks jp! Made an arbor for my heads, shown a few pages back. Still have to true up the spark plug holes when I get a chance at the shop. No mill at my house.. Yet lol planning to run dowel pins at this point. I prefer (in my head at least) having the mating surfaces of the head and barrel perfectly flat. If I need another set of heads on this set of barrels, I could hear drill a new set of pin holes right?
Title: Re: Yamaha rd350 road racer
Post by: Tune-A-Fishİ on Sep 08, 2016, 11:22:39
How about cutting in dowels for apposing head bolts?
Title: Re: Yamaha rd350 road racer
Post by: jpmobius on Sep 08, 2016, 17:49:48
You can still center up the head and drill for pins, and you can with care make additional heads fit the pins in an existing pinned cylinder but it isn't convenient.  Hollow dowels around the head bolts would be great, except there is still a fixturing problem with centering up the heads on the cylinders.  Not actually a problem, just a pain as regardless of how you do it, you have to make some sort of fixture to precisely center the head so you can bore holes for the dowels.  Little pins are easier because you can just take a gun drill (which is just a long twist drill) and drill between the fins on the head directly into the cylinder once you have it jigged up.  You could do the same through two of the head bolt bores if you don't mind the removal of so much material - Air cooled RD heads pretty commonly crack at the head bolt bores as it is - so personally I go with some small pins.  I use some small spring pins - also called tension pins, split pins expansion pins etc. - which are spring steel rolled into a cylinder with a split down one side.  Roll pins which are like a little sheet rolled in to a dowel would work fine as well or even just a plain steel solid pin.  I drill the holes through both head and cylinder to the diameter of an interference fit and then bore just the head to a tight slip fit.  That way the pins stay in the cylinder.  You have to be quite careful where you drill to make sure there is enough materiel to support the pin in the cylinder.
Title: Re: Yamaha rd350 road racer
Post by: Hurco550 on Sep 08, 2016, 17:57:02
You can still center up the head and drill for pins, and you can with care make additional heads fit the pins in an existing pinned cylinder but it isn't convenient.  Hollow dowels around the head bolts would be great, except there is still a fixturing problem with centering up the heads on the cylinders.  Not actually a problem, just a pain as regardless of how you do it, you have to make some sort of fixture to precisely center the head so you can bore holes for the dowels.  Little pins are easier because you can just take a gun drill (which is just a long twist drill) and drill between the fins on the head directly into the cylinder once you have it jigged up.  You could do the same through two of the head bolt bores if you don't mind the removal of so much material - Air cooled RD heads pretty commonly crack at the head bolt bores as it is - so personally I go with some small pins.  I use some small spring pins - also called tension pins, split pins expansion pins etc. - which are spring steel rolled into a cylinder with a split down one side.  Roll pins which are like a little sheet rolled in to a dowel would work fine as well or even just a plain steel solid pin.  I drill the holes through both head and cylinder to the diameter of an interference fit and then bore just the head to a tight slip fit.  That way the pins stay in the cylinder.  You have to be quite careful where you drill to make sure there is enough materiel to support the pin in the cylinder.

I was thinking about just doing the roll pin and drilling through the head into the barrel with it centered and bolted up, just as you had described. Hoping that I will only be running this set of heads on it, but if not a local salvage yard has probably 50 sets of rd top ends..... which I can get for about 50 bux a set. hoping it doesn't come to that though lol!
Title: Re: Yamaha rd350 road racer
Post by: Sav0r on Sep 08, 2016, 22:41:49
Wasn't say yours are junk, more so that I'd probably mess the machining up and I'd rather not do that to good cylinders.
Title: Re: Yamaha rd350 road racer
Post by: Hurco550 on Sep 08, 2016, 22:44:24
Wasn't say yours are junk, more so that I'd probably mess the machining up and I'd rather not do that to good cylinders.
Yeah, I was happy to have an extra set in case something went wrong. There was and is still a great possibility that it week happen
Title: Re: Yamaha rd350 road racer
Post by: Tune-A-Fishİ on Sep 08, 2016, 22:53:23
When you get a set all done you should sent them and the heads to restocycle for a vapor blast carbys too!
Title: Re: Yamaha rd350 road racer
Post by: Hurco550 on Sep 10, 2016, 00:24:59
Thanks again for the specs teazer. Tz o rings fit swell. Probably should have waited till they came in to cut the groove, but I'm impatient and not that wise ha
(http://uploads.tapatalk-cdn.com/20160910/f78a87f0dad78cdb694fac2cab089d7f.jpg)
Title: Re: Yamaha rd350 road racer
Post by: irk miller on Sep 10, 2016, 02:50:26
Orange is pretty.

Did this come from a dumpster?
Title: Re: Yamaha rd350 road racer
Post by: Hurco550 on Sep 10, 2016, 02:57:48
Orange is pretty.

Did this come from a dumpster?
Maybe they were at some point ha, then the guy put them on feebay
Title: Re: Yamaha rd350 road racer
Post by: Hurco550 on Sep 10, 2016, 03:10:53
When you get a set all done you should sent them and the heads to restocycle for a vapor blast carbys too!
Haven't said too much style wise on this, but I'm not going to go with a pristine finish on this one. The fairing has a been there and seen a thing or two look to it, and the bike does too, so for now I'm leaving it that way. Gonna build it mechanically sound (as much as a smoker can be) and leave the rest pretty sweaty. Kinda like I "found" an old race bike from back in the day and just washed it up.

That said, those vapor blasted parts you post do look great! Maybe if I decide to tear it back apart and make it shiny someday I'll go that route
Title: Re: Yamaha rd350 road racer
Post by: Tune-A-Fishİ on Sep 10, 2016, 08:49:05
Haven't said too much style wise on this, but I'm not going to go with a pristine finish on this one. The fairing has a been there and seen a thing or two look to it, and the bike does too, so for now I'm leaving it that way. Gonna build it mechanically sound (as much as a smoker can be) and leave the rest pretty sweaty. Kinda like I "found" an old race bike from back in the day and just washed it up.

That said, those vapor blasted parts you post do look great! Maybe if I decide to tear it back apart and make it shiny someday I'll go that route

Both great plans... I am doing much the same with the DeadTail. I will incorporate some shiny bits like the pipes and controls but that tank wheels an motor are not getting any paint or polish just a light scotchbright bath and showroom shine lol
Title: Re: Yamaha rd350 road racer
Post by: Hurco550 on Sep 12, 2016, 20:28:52
Got some parts piling up for this thing. Still need to get the crank and pistons, cylinders bored ect, but anyhow, I have a few more little projects that I can get done now.

520 chain conversion setup. Brass swingarm bushings, yz125 reeds. And a gasket set.
(http://uploads.tapatalk-cdn.com/20160912/dc19f02205709bd814909f2b3896f225.jpg)

And the real exciting part, full cdi ignition. It was a little spendy, but my old system was clear roached, so I could have nickle and dimed myself to where I would have had close to the cost in finding a used setup. Hopefully this will be a much more reliable system
(http://uploads.tapatalk-cdn.com/20160912/f4030abf8ce2953d3fd5eb5c7567a3ac.jpg)
Title: Re: Yamaha rd350 road racer
Post by: Tune-A-Fishİ on Sep 12, 2016, 21:09:45
I was happy to see that the Wassel ignition was a Vape unit, stuff has a good rep and I'm married to a Czech  :o
Title: Re: Yamaha rd350 road racer
Post by: teazer on Sep 13, 2016, 01:08:00
The Ignitech ignitions we use come for the Czech republic too.  They make good stuff in small companies.  Have you checked out their web site http://www.vape.cz/en/

Hurco.  It's getting close.  Soon be filling the shop with smoke.  BTW, I am pretty sure you can slip a set of RD400 gears on your trans shafts and keep your 350 clutch and sprocket, or go all RD400.  So many options for upgrades, so little time (and cash).
Title: Re: Yamaha rd350 road racer
Post by: Hurco550 on Sep 13, 2016, 11:19:46
thanks teaser. I will check with my salvage yard guy and see if he has any rd400 transmissions around that he would trade for the rd350 guts. often he would do a straight trade.

Im hoping the engine will be ready to fire in the next month or so, and be on the road by spring. not far on the engine "running", but the whole bike being road worthy in still a bit farther out..
Title: Re: Yamaha rd350 road racer
Post by: teazer on Sep 13, 2016, 12:38:13
Projects take longer than planned and it's the finishing details that really take time.  Big chunks are easy to do and see and small stuff takes time and is hard to see an progress.

When we think a project is 95% complete, in reality we are really only half way there. 
Title: Re: Yamaha rd350 road racer
Post by: Hurco550 on Sep 13, 2016, 12:44:14
When we think a project is 95% complete, in reality we are really only half way there.
Absolutely. And that's any project. I remember that feeling when I was building stamping dies, and the 95% 5% holds true there as well. My boss would come out day after day asking why the die that "looked" finished wasn't making parts.

 I don't have a real deadline for this one either, which doesn't really help. I'd sure like to take it to meltdown in March, but if it doesnt make it, it doesn't make it. I do all this as a hobby, and deadlines make it less enjoyable to me, thus making it less than a hobby and more like another job ha
Title: Re: Yamaha rd350 road racer
Post by: teazer on Sep 13, 2016, 12:57:43
It will be done when it's done and not a minute sooner. 

That's how my street bike projects are.
Title: Re: Yamaha rd350 road racer
Post by: VonYinzer on Sep 13, 2016, 13:13:45
Hey... At least your projects are in the same state as your garage lol.
Title: Re: Yamaha rd350 road racer
Post by: Hurco550 on Sep 13, 2016, 13:23:33
Hey... At least your projects are in the same state as your garage lol.
Ha yeah my projects and other people's too ;)
Title: Re: Yamaha rd350 road racer
Post by: Hurco550 on Sep 13, 2016, 19:53:12
Well, I don't think even Mr Rogers would call it a beautiful day in the neighborhood today. I have never fought unsticking an engine this bad.
(http://uploads.tapatalk-cdn.com/20160913/b931693f31f710fcf99f1cc5cc2e2114.jpg)

Finally got it loose, put it the jug down on the table, and this happened.. I must have fractured it while persuading the piston out.
(http://uploads.tapatalk-cdn.com/20160913/16d21d8a7a185f403e17bdc3bb7bed90.jpg)

And I uncovered this beauty in the mess..
(http://uploads.tapatalk-cdn.com/20160913/2648099b3bb5c5dc206c4fa01b85fd51.jpg)
Title: Re: Yamaha rd350 road racer
Post by: VonYinzer on Sep 13, 2016, 19:58:11
Dear god. Go back and punch the guy you bought that from in the neck.
Title: Re: Yamaha rd350 road racer
Post by: Hurco550 on Sep 13, 2016, 19:58:35
My spare right hand jug is already .040 over and the sleeve is getting a bit thin for comfort.
(http://uploads.tapatalk-cdn.com/20160913/dbf264cc2a39de8cbc0054d193003ea0.jpg)

Really thinking about just going this route and being done with it. Any of you guys used radjoot stuff? Not a bad price for brand new pistons and barrels. I'd just like some first hand advice

Look at this on eBay http://www.ebay.com/itm/291853498081
Title: Re: Yamaha rd350 road racer
Post by: Hurco550 on Sep 13, 2016, 20:01:35
Dear god. Go back and punch the guy you bought that from in the neck.
Ha, to be fair, when this all started, I was just planning on using this lump for the trans and build that r5 motor, but then I decided on the rd for the reed/part availability. May do a little research and see if I can run an rd top end on an r5 bottom end with the rd 6 speed
Title: Re: Yamaha rd350 road racer
Post by: clem on Sep 13, 2016, 21:43:21
You can do that RD top with RD 6 speed in R5 cases. I believe that vitos sells the RD cylinders with US spec porting. The Indian porting is not as good as USA.

Sent from my SAMSUNG-SM-G920A using DO THE TON mobile app (http://'https://siteowners.tapatalk.com/byo/displayAndDownloadByoApp?rid=89466')
Title: Re: Yamaha rd350 road racer
Post by: Ply318ci on Sep 14, 2016, 00:19:18


Really thinking about just going this route and being done with it. Any of you guys used radjoot stuff? Not a bad price for brand new pistons and barrels. I'd just like some first hand advice

Look at this on eBay http://www.ebay.com/itm/291853498081
[/quote]


From what I found on google a while ago Radjoot stuff is very detuned RD350 stuff so if you want at least stock RD performance you need to port the Radjoot barrels. If you were going to pot anyways then it might not be a big deal. It is because of low quality fuel in India I think. But I could be wrong.


Sent from my iPhone using Tapatalk
Title: Re: Yamaha rd350 road racer
Post by: teazer on Sep 14, 2016, 01:35:28
R5 and RD top ends are interchangeable.  R5 crank is supposedly slightly different to an RD.

RD has a different gear change cam than the R5, so it's better to start with an RD set of cases.

If you have to get barrels, look at a set of LC barrels and water pump set up if you can find one, or see if you can find a decent complete motor.  There are people on here that probably have whatever you need. Motors are heavy and expensive to ship, but if you get a good one, it might be worth the expense. If not, see what parts you need when you get into the bottom end and work out a plan of attack.
Title: Re: Yamaha rd350 road racer
Post by: Tune-A-Fishİ on Sep 14, 2016, 08:45:16
Agree it's the best direction for perf and service, but adding water is changing the whole blueprint not just adding a wall.

Long live air cooled motorcycles LOL kidding, but please don't wet yer pants  :o
Title: Re: Yamaha rd350 road racer
Post by: Hurco550 on Sep 14, 2016, 10:52:17
Lots to figure out/ decide. my r5 bottom end is in much better shape, but from what ive read the crank bearings for an rd350 have o ring grooves and the r5 doesn't, but vitos sells the crank as a drop in for a ds7, rd250 r5 and rd350, so that makes me assume that they are still interchangeable.

what I have in my possession are

a good set of r5 cases
a good rd350 complete trans, which could hopefully go in the cases, and I should have all the pieces since they are both complete.

The other thing is, once I get the rd350 motor torn clear down, there is still a possibility that the cases themselves are ok, im just worried that there may be cracking since there has obviously been water in the crank, it is an ohio bike and it has probably frozen in the winter time.

as far as the lc jugs, I was thinking obout that already, BUT I was just thinking that since all those lc models were only sold in Europe and Canada, parts may be a little scarce to come by in the states.

down the road I have "plans" to fabricate some rd350 watercooled heads as an add on, but that will be a ways off, I think for simplicity and budget sake, I should stay aircooled for now.

I will be having some port work done already, so I was hoping that the radjoot barrels would do ok. I was worried more about quality ect, but maybe I should just go ahead and buy the vitos setup and have the pistons too, by the time I buy the radjoot and a set of pistons, ill have only a little more money in the vitos kit, which I tend to trust more in the end
Title: Re: Yamaha rd350 road racer
Post by: Sav0r on Sep 14, 2016, 14:15:04
Those Indian cylinders are not well liked. I'd avoid them. Apparently the Vito's are better, but I have not compared nor seen either myself.

Title: Re: Yamaha rd350 road racer
Post by: clem on Sep 14, 2016, 15:02:00
The RD cranks have grooved seals not bearings. You can buy repop r5 style seals. It's actually only on the ignition side.

Sent from my SAMSUNG-SM-G920A using DO THE TON mobile app (http://'https://siteowners.tapatalk.com/byo/displayAndDownloadByoApp?rid=89466')

Title: Re: Yamaha rd350 road racer
Post by: Hurco550 on Sep 14, 2016, 15:02:14
Those Indian cylinders are not well liked. I'd avoid them. Apparently the Vito's are better, but I have not compared nor seen either myself.
I think for peace of mind I will buy a vitos kit and be done with it, I think if I go with the cheap Indian setup, I'd be mad at myself down the road for not just spending the extra 100 bucks for the us spec stuff
Title: Re: Yamaha rd350 road racer
Post by: teazer on Sep 14, 2016, 20:28:12
The RD cranks have grooved seals not bearings. You can buy repop r5 style seals. It's actually only on the ignition side.

Sent from my SAMSUNG-SM-G920A using DO THE TON mobile app (http://'https://siteowners.tapatalk.com/byo/displayAndDownloadByoApp?rid=89466')


Are you sure Clem?  RD cases are "grooved" on both sides for seals, but R5 are plain on both sides. RD cases are better IMHO but not a whole lot different.
Title: Re: Yamaha rd350 road racer
Post by: clem on Sep 14, 2016, 22:28:04
Teazer I'd have to go look at the parts book but  I thought that the only difference on the primary side of the crank/cases was the added o-ring with the square nub on the RD but the seals were the same. Edit, just looked and they are different part numbers but appear to both be smooth on the outside.
 I tried trimming an RD left side seal to get rid of the lip and it didn't work out well for me. Haha.

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Title: Re: Yamaha rd350 road racer
Post by: clem on Sep 14, 2016, 22:32:20
Good thing about the RD is that both seals are still available from Yamaha.

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Title: Re: Yamaha rd350 road racer
Post by: teazer on Sep 14, 2016, 22:44:03
Just as well because they also fit all the 72-80 TZ twins too.  TZ cases also have an extra pair of grooves to retain the center main bearings because the outers change to rollers to go with the straight cut primaries.  Other than that they are very similar to RD cases.  RD and TZ both have the raised ring around teh crank oil seals with a matching groove in the cases.  R5/DS7 do not.  They have seals which are smooth.
Title: Re: Yamaha rd350 road racer
Post by: clem on Sep 14, 2016, 22:46:32
This is why it's so good to have someone like you hanging around. Us young ones have to learn from somebody.

Sent from my SAMSUNG-SM-G920A using DO THE TON mobile app (http://'https://siteowners.tapatalk.com/byo/displayAndDownloadByoApp?rid=89466')
Title: Re: Yamaha rd350 road racer
Post by: Hurco550 on Dec 19, 2016, 15:44:42
Picked up a neat old fiber glass rd400 tank and some kinda road race style seat. I think it will fit the bill. Even though it's a balmy 12 degrees here in Ohio, I couldn't resist rolling it out for a few pics.
(http://uploads.tapatalk-cdn.com/20161219/bff1dbdf77b985e1c762d4b7df01543c.jpg)

(http://uploads.tapatalk-cdn.com/20161219/ac51a523beca6215bd078d292fe4446d.jpg)

(http://uploads.tapatalk-cdn.com/20161219/f3e254e230266d85eeb39ae8b5f5acd4.jpg)

Also picked up an rd250 motor just for the cases
Title: Re: Yamaha rd350 road racer
Post by: ridesolo on Dec 19, 2016, 17:06:08
Hey, that's going to look the real deal, bro.  Very nice.
Title: Re: Yamaha rd350 road racer
Post by: teazer on Dec 19, 2016, 18:22:03
Nice RS125/MT125 seat.  Did you say that the tank is fiberglass?  I just bought a dented RD400 steel tank which I have already cut the bottom out so I can panel beat it straight and take a mold off of it.  Any idea who made it or who has a mold for the top half?  I don't need the bottom, just the top for a drag race project.
Title: Re: Yamaha rd350 road racer
Post by: Hurco550 on Dec 19, 2016, 18:49:34
Nice RS125/MT125 seat.  Did you say that the tank is fiberglass?  I just bought a dented RD400 steel tank which I have already cut the bottom out so I can panel beat it straight and take a mold off of it.  Any idea who made it or who has a mold for the top half?  I don't need the bottom, just the top for a drag race project.
Hey thanks for letting me know what that seat was. I didn't think it was old Yamaha, but wasn't to sure what it was. This bike is enough of a mod podge of junk that I'm not to stuck on authenticity.
(http://uploads.tapatalk-cdn.com/20161219/a18b257e698efcc0499492084fc2d9bf.jpg)

The tank is one of 3 that the guy I got it from had made back in the late 70's or early 80's. He sold one and has the other on the bike still. I talk to him regularly, and will ask if the molds are still available.

If you get a chance, could you throe that stock 400 tank on a scale? I'm trying to figure out the weight difference from stock vs fiber glass.
Title: Re: Yamaha rd350 road racer
Post by: Hurco550 on Dec 19, 2016, 18:50:15
Hey, that's going to look the real deal, bro.  Very nice.
Thanks Cory!

As you can see your not missing much here in the tundra. Just cold and ice
Title: Re: Yamaha rd350 road racer
Post by: irk miller on Dec 19, 2016, 19:00:48
If you get a chance, could you throe that stock 400 tank on a scale? I'm trying to figure out the weight difference from stock vs fiber glass.
(https://www.powerliftinguniversity.com/wp-content/uploads/2015/07/science-bitch.jpg)
Title: Re: Yamaha rd350 road racer
Post by: JustinLonghorn on Dec 20, 2016, 08:50:09
This is looking all kinds of rad, sir.
Title: Re: Yamaha rd350 road racer
Post by: davedogg on Dec 20, 2016, 12:47:32
I don't know what you plan on doing with the bodywork. But it might be cool to keep the dirt (I mean patina) on this old road racer.
Title: Re: Yamaha rd350 road racer
Post by: Maritime on Dec 20, 2016, 13:09:05
Nice Levi, I like the way this is going.
Title: Re: Yamaha rd350 road racer
Post by: Hurco550 on Dec 20, 2016, 13:09:59
I don't know what you plan on doing with the bodywork. But it might be cool to keep the dirt (I mean patina) on this old road racer.

That's actually the exact plan =) digging the "been there, done that look" even if the bike hasn't... yet.

Id really like to know the history on the fairing itself. Im pretty sure its tz, but may have been a privateer team.

it reads "hoyt-clagwell Yamaha" on the side.

hoyt clagwell was the fictional brand of tractor on the green acres tv show. I think someone had a sense of humor back in the day
Title: Re: Yamaha rd350 road racer
Post by: canyoncarver on Dec 20, 2016, 13:36:38
That's actually the exact plan =) digging the "been there, done that look" even if the bike hasn't... yet.

Id really like to know the history on the fairing itself. Im pretty sure its tz, but may have been a privateer team.

it reads "hoyt-clagwell Yamaha" on the side.

hoyt clagwell was the fictional brand of tractor on the green acres tv show. I think someone had a sense of humor back in the day


I loved that show as a kid. 
Title: Re: Yamaha rd350 road racer
Post by: teazer on Dec 20, 2016, 14:47:43

The tank is one of 3 that the guy I got it from had made back in the late 70's or early 80's. He sold one and has the other on the bike still. I talk to him regularly, and will ask if the molds are still available.

If you get a chance, could you throe that stock 400 tank on a scale? I'm trying to figure out the weight difference from stock vs fiber glass.


I already cut the bottom out, but I'll see if it's still in the junk pile and if so, I'll weigh top and bottom together.  Today's thought is to simply weld back the rear section of the bottom to make a small tank and leave the front as an empty shell.  For teh class we intend to run this thing, the tank has to be at least 1 gallon and that roughly 8" x 8" x 4"  or 0.15 cubic feet if I calculated that correctly.  1 gallon is 0.133 cubic feet, so 1.5 should be enough.  It only needs a liter of gas per run or less,but gotta stay within the rules..
Title: Re: Yamaha rd350 road racer
Post by: teazer on Dec 20, 2016, 15:08:30
BTW, do RD350 heads use long reach or short reach plugs?  I know that R5 are short and RD400 are long, but I don't know about RD350s.

I need a pair of heads for the drag bike and would prefer  a pair of RD350 IF they take long plugs.  If not, I'll have to get a pair of small square heads machined out of billet.
Title: Re: Yamaha rd350 road racer
Post by: Hurco550 on Dec 20, 2016, 15:13:03
BTW, do RD350 heads use long reach or short reach plugs?  I know that R5 are short and RD400 are long, but I don't know about RD350s.

I need a pair of heads for the drag bike and would prefer  a pair of RD350 IF they take long plugs.  If not, I'll have to get a pair of small square heads machined out of billet.
(http://uploads.tapatalk-cdn.com/20161220/45fdfefa0016a517d15bf61924f0967d.jpg)

This is an rd 350 head. Just traded my r5 heads literally yesterday for another set of rd heads at the savage yard so I don't have a set to compare lol
Title: Re: Yamaha rd350 road racer
Post by: teazer on Dec 20, 2016, 15:15:18
Thanks.  I'll grab a set from somewhere.
Title: Re: Yamaha rd350 road racer
Post by: Hurco550 on Dec 20, 2016, 15:17:16
Thanks.  I'll grab a set from somewhere.
Let me know, I can get a few pretty easily if you can't source them. EBay does have them pretty cheap at times though
Title: Re: Yamaha rd350 road racer
Post by: Redbird on Dec 20, 2016, 16:35:47
Levi, the spare RD400 tank I have weighs in at 9lbs on the digital bathroom scale.
And that's minus fuel tap and cap.
Title: Re: Yamaha rd350 road racer
Post by: irk miller on Dec 20, 2016, 17:41:24
(http://images-cdn.9gag.com/photo/a9dN4e1_700b.jpg)
Title: Re: Yamaha rd350 road racer
Post by: Hurco550 on Dec 20, 2016, 17:52:48
Levi, the spare RD400 tank I have weighs in at 9lbs on the digital bathroom scale.
And that's minus fuel tap and cap.
Thanks man. As I'm reading this I'm on my way to Georgia for the holidays, so I won't be able to weigh mine until after I get back, but I'm willing to bet a dollar and a high five that the glass one weighs less than half that
Title: Re: Yamaha rd350 road racer
Post by: der_nanno on Dec 21, 2016, 06:20:01
Nice project! I especially like your fixture for squaring up both top and bottom of the cylinder. I'll borrow that idea and put it to good use on my own (racing) RD ...
Title: Re: Yamaha rd350 road racer
Post by: davedogg on Dec 21, 2016, 11:08:58
RD350 takes shorter plugs than the 400. Unless you are running DG heads on a RD350.
Title: Re: Yamaha rd350 road racer
Post by: jpmobius on Dec 21, 2016, 11:40:26
+1.  R-5 (and Ds7) and all RD 350/250's use the short reach B*HS (NGK) plugs and RD400's use the long B*ES plugs.  DG's (also Ottoco and now HVC cycle) also use the long plugs.  Also the early 350 heads have the inside cooling fin interrupted by the head bolts where the later versions have a continuous "wavy" fin that curves to miss the bolts.  Those are the preferred heads at least for me as they seem to be less prone to cracking and have greater beam strength for clamping the gasket uniformly - a real weakness with all the 350 heads.
Title: Re: Yamaha rd350 road racer
Post by: Hurco550 on Dec 29, 2016, 17:35:11
Nice project! I especially like your fixture for squaring up both top and bottom of the cylinder. I'll borrow that idea and put it to good use on my own (racing) RD ...
Thanks! Can't take credit for the design though, I was inspired by this write up.

http://justyamahard350.com/articles/dale_1.htm

One thing I did differently though was made it so the all thread went clear through the spindle vs just bolting into the arbor. Just a little extra safe guard to help hold everything together
Title: Re: Yamaha rd350 road racer
Post by: der_nanno on Dec 29, 2016, 17:56:01
Oh I remember the article, even though I must have read it ages ago!
Title: Re: Yamaha rd350 road racer
Post by: Hurco550 on Dec 29, 2016, 17:57:12
Oh I remember the article, even though I must have read it ages ago!
I've read it through several times, now to put it into practice
Title: Re: Yamaha rd350 road racer
Post by: Hurco550 on Dec 31, 2016, 00:46:33
Levi, the spare RD400 tank I have weighs in at 9lbs on the digital bathroom scale.
And that's minus fuel tap and cap.
Mine weighs in at 3.4 with the caps and taps in place. Thanks again for the numbers
Title: Re: Yamaha rd350 road racer
Post by: Redbird on Jan 04, 2017, 16:20:21
Prego ;)
Title: Re: Yamaha rd350 road racer
Post by: teazer on Jan 04, 2017, 20:47:23
How will you seal that tank against modern ethanol based fuels? I sealed an old tank recently with Caswell but it was a PIA to scour the inside surface to get a good key for the coating.

Just sell if to me and I'll cut the bottom out and use it as a shell for our drag race bike.  See how I saved you there.... ;-)

I'm kidding about the last bit, but it will need to be sealed somehow.
Title: Re: Yamaha rd350 road racer
Post by: Hurco550 on Jan 04, 2017, 20:54:58
How will you seal that tank against modern ethanol based fuels? I sealed an old tank recently with Caswell but it was a PIA to scour the inside surface to get a good key for the coating.

Just sell if to me and I'll cut the bottom out and use it as a shell for our drag race bike.  See how I saved you there.... ;-)

I'm kidding about the last bit, but it will need to be sealed somehow.
Haha I see what you did there. I haven't thought about sealer yet, but, for the short term the plan against ethanol will be to run aircraft fuel, as for the compression values I will likely be running (need to pick your brain on that one too) will require high test gas, and the local airport is a stone's throw from my house. I generally get fuel there for winter storage anyhow. I wish there were some of those ethanol free gas stations around here like there are in the south....
Title: Re: Yamaha rd350 road racer
Post by: irk miller on Jan 04, 2017, 21:07:40
No need for avgas, you have non-ethanol options.  Avgas is usually 100 octane.  Too bad you don't have options like I have options, but you have options.
Title: Re: Yamaha rd350 road racer
Post by: Hurco550 on Jan 04, 2017, 21:11:59
No need for avgas, you have non-ethanol options.  Avgas is usually 100 octane.  Too bad you don't have options like I have options, but you have options.
I,ve sen that site before, but I'm in Marion, and that Delaware marina (the closest one) is about 40 minutes of pain in the butt highway to get to. For now, being as I pass the airport twice a day, I'll use that for the time being. Maybe make a run to the marina with a few "stock up" cans when the time comes. Thanks man!
Title: Re: Yamaha rd350 road racer
Post by: irk miller on Jan 04, 2017, 21:29:22
If you're worried about roughing up the interior of the tank for Caswell, then put a handful of drywall screws in the tank and tumble it for an hour. 
Title: Re: Yamaha rd350 road racer
Post by: Tune-A-Fishİ on Jan 04, 2017, 23:26:19
You should be able to find some VP U4 in 5 gallon cans close by.

Avgas is 100LL (low lead) dry gas.
Title: Re: Yamaha rd350 road racer
Post by: Hurco550 on Jan 04, 2017, 23:36:04
You should be able to find some VP U4 in 5 gallon cans close by.

Avgas is 100LL (low lead) dry gas.
I'm not on the up and up on leaded vs. Unleaded. Your saying I'd want to run leaded?
Title: Re: Yamaha rd350 road racer
Post by: Tune-A-Fishİ on Jan 04, 2017, 23:46:59
I'm not on the up and up on leaded vs. Unleaded. Your saying I'd want to run leaded?

I'm not sure if unleaded would hurt it but it ran on regular in the day which was 90-92 octane leaded fuel. Dry gas has less lubricity.
Title: Re: Yamaha rd350 road racer
Post by: teazer on Jan 05, 2017, 01:27:23
VP U4.4 has alcohol and whole lot of other chemical soup and it's 90 bucks a 5 gallon pail.  Stay away from slow burning avgas designed for engines that peak at around 5,000.

CR 17:1, and a load of VP C12 and you should be golden.  OK, so not so high. I got 20mm domes for one RD and plan on using 18mm domes in the drag race motor.  Compression is related to exhaust port height and exhaust efficiency. With high port and poor exhaust, the effective compression is very low.  If the pipe is working well and creating a perfectly timed stuffing wave, the effective compression is much higher.

The other variable ( there's more than one, but let's keep this simple) is squish band or more specifically Mean Squish Velocity which is a function of squish width and depth and angle and RPM.  For low revs, we use a tight squish band and/or a wide one.  For a top end motor we need a narrower band to keep MSV down at higher engine speeds.

For a slightly warmed over bike with mild porting, compression can be raised a little but not too much. 

Title: Re: Yamaha rd350 road racer
Post by: hooligan998 on Jan 05, 2017, 01:58:55
I'm late to the game, but a great read so far!  In like sin.
Title: Re: Yamaha rd350 road racer
Post by: irk miller on Jan 05, 2017, 07:14:47
Or just make it simple and throw a handful of drywall screws in the tank, tumble it for an hour, line it with Caswell, and go to your nearest gas station for a fill up. 
Title: Re: Yamaha rd350 road racer
Post by: Tune-A-Fishİ on Jan 05, 2017, 10:03:33
It's a race machine and race machines need race gas ⛽️LOL get some oxygenated VP gol dang it


Sent from my iPhone using DO THE TON (http://r.tapatalk.com/byo?rid=89466)
Title: Re: Yamaha rd350 road racer
Post by: Hurco550 on Jan 05, 2017, 10:54:21
Or just make it simple and throw a handful of drywall screws in the tank, tumble it for an hour, line it with Caswell, and go to your nearest gas station for a fill up.

dangit, I think the artist may be right again haha.

will all the old sealer need be removed before, or just roughed up to accept the new caswell?
Title: Re: Yamaha rd350 road racer
Post by: johnu on Jan 05, 2017, 11:05:56
Haha I see what you did there. I haven't thought about sealer yet, but, for the short term the plan against ethanol will be to run aircraft fuel, as for the compression values I will likely be running (need to pick your brain on that one too) will require high test gas, and the local airport is a stone's throw from my house. I generally get fuel there for winter storage anyhow. I wish there were some of those ethanol free gas stations around here like there are in the south....

I don't know if there are any Sunnoco dealers in your area but I'm using their 110 leaded fuel in all of my bikes now.  I'm done with that ethanol crap.
Title: Re: Yamaha rd350 road racer
Post by: Hurco550 on Jan 05, 2017, 20:13:28
VP U4.4 has alcohol and whole lot of other chemical soup and it's 90 bucks a 5 gallon pail.  Stay away from slow burning avgas designed for engines that peak at around 5,000.

CR 17:1, and a load of VP C12 and you should be golden.  OK, so not so high. I got 20mm domes for one RD and plan on using 18mm domes in the drag race motor.  Compression is related to exhaust port height and exhaust efficiency. With high port and poor exhaust, the effective compression is very low.  If the pipe is working well and creating a perfectly timed stuffing wave, the effective compression is much higher.

The other variable ( there's more than one, but let's keep this simple) is squish band or more specifically Mean Squish Velocity which is a function of squish width and depth and angle and RPM.  For low revs, we use a tight squish band and/or a wide one.  For a top end motor we need a narrower band to keep MSV down at higher engine speeds.

For a slightly warmed over bike with mild porting, compression can be raised a little but not too much.
Im having a hard time finding info on what exactly the rd350 head cc should be. Should I make it the same as stock after I do the head/squish machining work? It makes sense with raising the ex. Port having less effective compression.

I also just printed this off today. I'm about 10 pages in at this point already learning alot, but I think my brain may be bleeding a bit as well from the volume of info ha
(http://uploads.tapatalk-cdn.com/20170106/c38cbced7ced37f688dd17a096a695d3.jpg)
Title: Re: Yamaha rd350 road racer
Post by: teazer on Jan 05, 2017, 21:20:26
Great book.  That man was ahead of his time in many ways.  Of course, things have moved on since then and there is more knoweldge in teh pool to dip your toe.

A.G. Bell is a good read - probably easier to read.

Q: do you plan to race it, do track daze or just ride it hard and put it away wet?  If it's for teh race track, race gas is a good solution but you don't need super high octane levels. C12 is fine for most things.  My race GT750 will run happily on 93 octane street gas but I have run it on U4.4 (wow) and set a new personal best with a drum of old C11 pre-mix. 

For a high comp race type motor C12 is fine.
Title: Re: Yamaha rd350 road racer
Post by: Hurco550 on Jan 05, 2017, 21:27:06
Great book.  That man was ahead of his time in many ways.  Of course, things have moved on since then and there is more knoweldge in teh pool to dip your toe.

A.G. Bell is a good read - probably easier to read.

Q: do you plan to race it, do track daze or just ride it hard and put it away wet?  If it's for teh race track, race gas is a good solution but you don't need super high octane levels. C12 is fine for most things.  My race GT750 will run happily on 93 octane street gas but I have run it on U4.4 (wow) and set a new personal best with a drum of old C11 pre-mix. 

For a high comp race type motor C12 is fine.
I'll look into that other book as well!

The plan is for a street toy bike. I'm not a skilled enough rider for track days or racing. The goal is for the longest trip to probably be the pass from where I stay at barber to the show itself. I'm guessing a 15 mile stretch at best.

Something to zip around here and put away wet, or make the whooping 4.5 mile ride into work now and again, but as I said, a street toy, not a daily rider

Also, as my fuel ignorance will show, what's c12. Thinking through it again, I'd probably be best off to seal the tank and be able to run on 5% ethanol 93 octane pump gas
Title: Re: Yamaha rd350 road racer
Post by: clem on Jan 05, 2017, 23:14:06
Levi, when you decked your cylinders for the O rings I am assuming that you removed the indent for the original gaskets? That right there was a step in the right direction to fix the squish.

Sent from my SAMSUNG-SM-G920A using DO THE TON mobile app (http://'https://siteowners.tapatalk.com/byo/displayAndDownloadByoApp?rid=89466')

Title: Re: Yamaha rd350 road racer
Post by: teazer on Jan 06, 2017, 00:10:08
That's good to hear.  The objective is a bike that is fun to ride.  Light and good brakes and exciting street performance.  So we are looking at mild porting with say slightly taller and wider exhaust port, stock transfer ports and cleaned up inlets with better reeds. Could be OEM with YZ125 reed petals or YZ85 sided single petal reed cages or even Banshee/RZ350 reed blocks.  Nothing outrageous.

Slightly higher that stock compression but nothing outrageous and an O ring head/barrel seal with heads centered on the bores.  93 octane street gas should be sufficient for that combo. Clem is right about squish and head machining. 

Just for the record:
VP race fuels
https://vpracingfuels.com/racing-fuels/

http://www.racefuel.com/vp-c12-racing-fuel-108-octane/

http://www.racefuel.com/vp-u4-4-racing-fuel-103-octane/

http://www.racefuel.com/vp-101-street-legal-unleaded-101-octane/



Sunoco

http://www.sunocoracefuels.com/fuels/compare-fuels

http://www.sunocoracefuels.com/fuels

And just to put it into context:  https://drive.google.com/file/d/0B7r8KNzyxX04WklDQTZDYnFyblE/view
Title: Re: Yamaha rd350 road racer
Post by: irk miller on Jan 06, 2017, 00:45:15
(https://i.ytimg.com/vi/adVpp4Pibs8/maxresdefault.jpg)
Title: Re: Yamaha rd350 road racer
Post by: bradj on Jan 06, 2017, 01:54:40
Bet you cant top this
Title: Re: Yamaha rd350 road racer
Post by: Hurco550 on Jan 06, 2017, 08:18:13
Bet you cant top this
I don't know if I can't, but I sure don't want to
Title: Re: Yamaha rd350 road racer
Post by: VonYinzer on Jan 06, 2017, 09:26:00
Bet you cant top this

Title: Re: Yamaha rd350 road racer
Post by: Hurco550 on Jan 06, 2017, 12:32:38
Levi, when you decked your cylinders for the O rings I am assuming that you removed the indent for the original gaskets? That right there was a step in the right direction to fix the squish.

yep, on my first try I did just as you said, however, im gonna grab a new set of barrels, as one of mine is on its last over bore, and im thinking about going a little different with this one. I think instead of taking the lip out, I am gonna leave it there and instead of dowelling the head to the barrel, I will cut a raised lip in the head for alignment, similar to what dg did with their sunburst heads..

any thoughts on that would be helpful..

That's good to hear.  The objective is a bike that is fun to ride.  Light and good brakes and exciting street performance.  So we are looking at mild porting with say slightly taller and wider exhaust port, stock transfer ports and cleaned up inlets with better reeds. Could be OEM with YZ125 reed petals or YZ85 sided single petal reed cages or even Banshee/RZ350 reed blocks.  Nothing outrageous.

Slightly higher that stock compression but nothing outrageous and an O ring head/barrel seal with heads centered on the bores.  93 octane street gas should be sufficient for that combo. Clem is right about squish and head machining. 

Just for the record:
VP race fuels
https://vpracingfuels.com/racing-fuels/

http://www.racefuel.com/vp-c12-racing-fuel-108-octane/

http://www.racefuel.com/vp-u4-4-racing-fuel-103-octane/

http://www.racefuel.com/vp-101-street-legal-unleaded-101-octane/



Sunoco

http://www.sunocoracefuels.com/fuels/compare-fuels

http://www.sunocoracefuels.com/fuels

And just to put it into context:  https://drive.google.com/file/d/0B7r8KNzyxX04WklDQTZDYnFyblE/view

I already have a set of yz125 reed petals in the shop waiting, as well as a banshee manifold with a crossover tube. I still have your notes on ports as far as the pipes that you ran the numbers on for me (thanks again).

Also, as that goes, ive been scouring the net and asking around about the Rajdoot barrels that are coming up online. They are cheap and I could put together a top end with those barrels and prox banshee pistons (with the tang removal) for half of what the vitos kit is...

I guess what im thinking, is that if im having porting done anyhow, why not start with the indian de tuned jugs......

again, any advice would be welcomed ;)
Title: Re: Yamaha rd350 road racer
Post by: teazer on Jan 06, 2017, 16:29:22
I like the idea of setting the head into that recess with O rings to seal them. That's what I plan on doing with mine, but I need to be really careful that the two steps are right.  Problem with a stock 350 arrangement is that the head bows as it's tightened down over the head gasket. Mine will have to be machined out of billet blocks 4" x 4" x 1.5" so I can use TZ aluminum head bolts/nuts.

ebay has some Chinese made new RD350 barrels for 150 shipped per pair.  Mine were damaged in transit and have slightly bent fins, but the casting work is amazing.  That said, the ports need to be cleaned up somewhat to get them where you want them.

Another possibility is to bore yours to 66mm and/or have them nicasil plated like a TZ except the plating is on the liner and not on bare aluminum.

Choices, choices...  Did you read the safety sheet on that race gas?  It's scary shit.. 
Title: Re: Yamaha rd350 road racer
Post by: teazer on Jan 06, 2017, 16:31:26
Bet you can't top this

Been there, done that. - once or twice or 4 times at Daytona - turned out to be the tiniest minor air leak between inlet manifold and barrels.
Title: Re: Yamaha rd350 road racer
Post by: Hurco550 on Jan 06, 2017, 16:47:24


I like the idea of setting the head into that recess with O rings to seal them. That's what I plan on doing with mine, but I need to be really careful that the two steps are right.  Problem with a stock 350 arrangement is that the head bows as it's tightened down over the head gasket. Mine will have to be machined out of billet blocks 4" x 4" x 1.5" so I can use TZ aluminum head bolts/nuts.

ebay has some Chinese made new RD350 barrels for 150 shipped per pair.  Mine were damaged in transit and have slightly bent fins, but the casting work is amazing.  That said, the ports need to be cleaned up somewhat to get them where you want them.

Another possibility is to bore yours to 66mm and/or have them nicasil plated like a TZ except the plating is on the liner and not on bare aluminum.

Choices, choices...  Did you read the safety sheet on that race gas?  It's scary shit..

I'll have to do a bit more o ring research, but my plan is that the mating surface on the head and the o ring step is a precision match, or about .001" less so that the head sits flush where the bolts draw it down and does not bow like the stock setup does... Also, that way I can bolt those heads onto different barrels without having to mod the barrels themself if need be.


If you are saying the Chinese jugs are suitable for use, that's good enough for me, as long as they can be ported to spec without much issue.. I'd rather stay away from the cost of nikisil and start with a fresh set of barrels if I can.... I'm also still thinking about making some billet water cooled heads in the future, perhaps that are adapted to use banshee cool head inserts... That's down the road though. I know a company did it back in the earlier years (I think the name was revco??) But they didn't use a water pump, it was a thermo siphon deal. I was thinking about using a tz water pump in place of the oil meter, or von yinzer also mentioned an electric water pump. He also mentioned that water cooled heads may not be an upgrade unless jacketing the barrels as well... At which point I would guess finding a 350 lc top end would be a far better option anyhow.


I need to look at that sheet on the race gas, I didn't get to that yet today lol
Title: Re: Yamaha rd350 road racer
Post by: teazer on Jan 06, 2017, 18:30:55
Water cooling is a great upgrade for a bike that is ridden really hard or in unbearable heat, but for what you describe, may not be so necessary (or cheap).  I would stay away from TZ parts except to see how they were designed.  Port shapes are old school and so are teh large water passages.  An LC top end would be nice insurance, but not cheap and needs a water pump and radiator etc.  Water pump can be TZ style or LC/RZ style or electric.  There's a reasonably priced Bosch unit for VW's and Audis but unless you have the spare dollars burning a hole in your pocket, maybe just keep an eye open for an LC350 top end during the off season.

I have a few hours into porting a set of Chinese barrels and no way to know if the metal is cheesium until I run them in anger. I read somewhere on another forum that RD350s have thinner liners than an RZ and cannot be bored as large, but I don't have that reference.  If possible, use the barrels you have.
Title: Re: Yamaha rd350 road racer
Post by: jpmobius on Jan 06, 2017, 18:31:34
I think you will find that the bending issue with the heads pretty much disappears with the o-rings.  If you machine the head to look like it has a permanent original copper gasket than certainly the bending effect will still be present as the bolt holes will still overhang contact surfaces that hold the o-ring.  This presumes you leave a space between the cylinder and head where the bolt passes through.  As long as you don't over torque the head nuts, the o-ring should still seal.  If you machine the heads so that the height of the step is the same as the old gasket recess, then the bending problem disappears and you now rely on the beam strength of the head between the bolts offering sufficient clamping pressure.  Which is what you do regardless - but you will be eliminating the problem that exists with the stock arrangement.  If you are facing off the top of the cylinders, keep the old gasket recess as shallow as possible - you only need it to be deep enough to register the new flange you are machining into the heads.  Keeping the recess and the corresponding flange as shallow as possible will let you machine the least amount of material off of the heads.  You want to keep the heads as thick as possible to end up with the maximum beam strength.
Title: Re: Yamaha rd350 road racer
Post by: clem on Jan 06, 2017, 21:06:22
You could always set up you cylinders to use the RD400 gaskets too.
One thing on the overseas cylinders that may be a little insurance is to pin the sleeves to the cylinders. The Internet says that they may move around in there. Teazer may know for sure pretty soon and he will be able to enlighten us all.

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Title: Re: Yamaha rd350 road racer
Post by: Hurco550 on Jan 08, 2017, 20:35:59
I'm thinking that I'll go with the centering design using a step turned into the head with the same height as the depth of the step in the barrel. As far as making the step as shallow as possible, all of the stock barrels that I have at the moment set right at .027" from the top down to the stock gasket surface (measured with depth micrometers). I don't know that I'd want to use much less of a step than that to register it? Maybe cut it in half and use .014" or so, but that's getting to be a pretty miniscule amount id think, and I'd worry about the the o ring itself holding it up too high until it is torqued into the centered position.

I also re made my arbor to do the head machining on. I wasn't super happy with how my first one turned out, so I made another one the way I should have in the first place, by single point threading instead of a bolt drilled and tapped into the arbor itself. (It's nice having a friend that lets you use his mill and lathe. My old south bend doesn't have metric thread pitch change gears)
(http://uploads.tapatalk-cdn.com/20170109/d5bf03f0e08506c681d1af3cb696a90b.jpg)

I went ahead and milled the spark plug surfaced to insure that they are parallel to the gasket surface. I only took about .003", just enough to clean them up.
(http://uploads.tapatalk-cdn.com/20170109/4c19bb84833a53cd8cdf5b4529f14266.jpg)

(http://uploads.tapatalk-cdn.com/20170109/1b6923e984cfa5368d233cc3e3764f2b.jpg)

The heads have been warped at some point as shown by an indicator. They vary by about .004" on the indicator, but that can be fixed when turning.
(http://uploads.tapatalk-cdn.com/20170109/573ef0dcff57f5f4c5c1b958712a82a5.jpg)

I was also going to pick you guys brain on rd250 heads. I have a set here that I could machine to suit, and being as they have a smaller combustion chamber, I'd have more material to shape the squish/ combustion chamber to whatever need may be. The only thing I'm not sure of is whether they have the same amount of material as the 350 heads and if not, will machining them to the specs needed will remove to much weakening them. Any insight would be much appreciated.

Also, I'm itching to work on this thing, but I have more ambition than cash at the moment. I picked up an rd250 bottom end recently with a descent crank in it. I'm not planning on running that crank as it would need rebuilt, so I'll probably still go with the vitos unit, but the question is, can I use the crank to setup my top end (squish) and then still have the same results when I rebuilt the bottom end with a new crank, or should I just wait until I can fork out the cash for a crank as well. I'm just not able to bite the bullet and buy a crank AND a top end  right now, but I have a little time on my hands, at least at the moment ha
Title: Re: Yamaha rd350 road racer
Post by: jpmobius on Jan 08, 2017, 21:10:50
the 250 and 350 cranks are identical.  250's have a larger ratio primary drive, so you have to swap out the gear, but the actual cranks are the same.  Nice machine work!  I've never measured how much the o-ring holds the head off the cylinder, but it is very small.  Feels like nothing when assembling, but as you point out, the full step is quite small anyway so making is smaller is a pretty small gain.
Title: Re: Yamaha rd350 road racer
Post by: teazer on Jan 09, 2017, 01:54:09
Nice work.  I may have to send a set of heads for you to machine for me... :-)


Quote
I've never measured how much the o-ring holds the head off the cylinder,...
Should be zero. If not, it won't seal properly.

The ring is round in cross section and it deforms into the groove which has a square cross section. Any pressure that leaks in there should cause further ring deformation to maintain the seal.

The seal groove must be square.  Do not try to make it round and expect the O ring to sit in there and seal it off. I "inherited" a set of expensive heads like that that leak profusely as they blow out seals. The domes/inserts will have to be redesigned to make them work.
Title: Re: Yamaha rd350 road racer
Post by: jpmobius on Jan 09, 2017, 02:02:01
Should be zero. If not, it won't seal properly.

The ring is round in cross section and it deforms into the groove which has a square cross section. Any pressure that leaks in there should cause further ring deformation to maintain the seal.

The seal groove must be square.  Do not try to make it round and expect the O ring to sit in there and seal it off. I "inherited" a set of expensive heads like that that leak profusely as they blow out seals. The domes/inserts will have to be redesigned to make them work.
Indeed!  to clarify, I was meaning the distance the ring sits proud of the groove with the head off.  I guess easy enough to know by subtracting the groove depth from the ring dia. 
Title: Re: Yamaha rd350 road racer
Post by: irk miller on Jan 09, 2017, 07:17:04
I need that test indicator.  You and your fancy measuring devices.   8)
Title: Re: Yamaha rd350 road racer
Post by: Shoeman on Jan 09, 2017, 07:37:25
Fantastic discussion gentlemen.   All I'll add is that I worked on a set of the India made cylinders back in 2010 for a customer and one of the sleeves was offset to the port castings by several mm.  I can't recall just how much, and the porting requested took care of the issue anyways.   QC may have improved since then though.  Oh, and they shipped two left cylinders initially.  Oops.
Title: Re: Yamaha rd350 road racer
Post by: Hurco550 on Jan 09, 2017, 08:24:44


Nice work.  I may have to send a set of heads for you to machine for me... :-)

Should be zero. If not, it won't seal properly.

I'd be happy to machine some for you once I make sure I don't scrap these ones.

And yeah I meant before assembly as far as the o ring sitting up to high to allow it to register before torqued. I still have the tz groove dimensions you sent me, that's what I'm planning on using.

Indeed!  to clarify, I was meaning the distance the ring sits proud of the groove with the head off.  I guess easy enough to know by subtracting the groove depth from the ring dia.
Exactly lol ill measure today.
I need that test indicator.  You and your fancy measuring devices.   8)
That one is actually just the fairly cheap spi. I've used to to build several progressive stamping dies. If it's good enough for that is good enough for use on the old south bend lol.
Fantastic discussion gentlemen.   All I'll add is that I worked on a set of the India made cylinders back in 2010 for a customer and one of the sleeves was offset to the port castings by several mm.  I can't recall just how much, and the porting requested took care of the issue anyways.   QC may have improved since then though.  Oh, and they shipped two left cylinders initially.  Oops.
Any possible way you could contact that customer and see if he still has the bike and how they are holding up?
Title: Re: Yamaha rd350 road racer
Post by: teazer on Jan 09, 2017, 10:11:35
Fantastic discussion gentlemen.   All I'll add is that I worked on a set of the India made cylinders back in 2010 for a customer and one of the sleeves was offset to the port castings by several mm.  I can't recall just how much, and the porting requested took care of the issue anyways.   QC may have improved since then though.  Oh, and they shipped two left cylinders initially.  Oops.

This set is rather like that too.  One liner is almost 2mm lower than the other and some voids between liner and ports to take care of.  Porting will lean up most of that plus maybe some devcon in the intake to smooth flow around the step.
Title: Re: Yamaha rd350 road racer
Post by: Tune-A-Fishİ on Jan 09, 2017, 10:44:39
Izarah Rosetta Stone for this language  :-\
Title: Re: Yamaha rd350 road racer
Post by: Hurco550 on Jan 09, 2017, 12:37:59
Izarah Rosetta Stone for this language  :-\

its not a language as much as it is a side effect to the disease known as twostrokefluenza.
Title: Re: Yamaha rd350 road racer
Post by: ridesolo on Jan 09, 2017, 13:37:58
its not a language as much as it is a side effect to the disease known as twostrokefluenza. 

I heard somebody say that a 20cc injection of straight Yamalube will cure it, but that's just propaganda.  Instead of curing the twostrokefluenza it creates an addiction and you are hooked for life.  Too bad, too, because many of them use to be responsible citizens and now they are addicted hooligans.  A real shame...   
Title: Re: Yamaha rd350 road racer
Post by: Shoeman on Jan 09, 2017, 19:29:35
I just emailed the gent for his experience with them.  I reread my old correspondences with him and they were actually Chinese manufacture.  I also had noted that one intake port floor was a very rough casting that had a large void where it should have met the liner.  If I had not been lowering that port, it would have left a gross enough mis-match to impeded the intake flow.  Of the three cylinders I saw, only one was acceptable as is in my opinion at the time.  I'll let you know what I hear.
Title: Re: Yamaha rd350 road racer
Post by: Hurco550 on Jan 09, 2017, 20:07:32
Thanks shoeman! Still considering them. Here is what I have to work with at the moment, and trying to decide whether to use them. The two usable cylinders I have are the left one I pulled off the bike which is stock bore of 64.02mm needing a rebore. I already surfaced the head removing the original gasket groove and added the o ring grove. The second barrel I picked up has already had 4 over bores and is sitting at 65.04mm. If I use this pair, I'll have to surface the second head the same and add dowel pins which is no big deal, I'm just more worried about the lack of liner left, and the fact that they will be miss matched bore sizes. That is unless I take the other bore out to the same size, which seems wasteful as far as using up so many over bores just to make a matching set.

Thoughts from the gurus?

(http://uploads.tapatalk-cdn.com/20170110/8b4de2742475fdf762f25fc4bc15e26b.jpg)
Title: Re: Yamaha rd350 road racer
Post by: teazer on Jan 09, 2017, 20:15:24
I have bought used RD400 motors with 1mm over on one side and stock on the other side.  I know it sounds all wrong, but in the real world on a street motor it makes less difference than you might imagine. 

It's not the "right way", but we live in the real world and funds and time are not infinite resources.
Title: Re: Yamaha rd350 road racer
Post by: Shoeman on Jan 09, 2017, 21:29:45
Teazer hit the nail on the head.  I would not mis-match bores on a race bike that lives at 10k most of the time, but you're not building that bike.  I think I still have some 350 cylinders under my bench.  I'll look and if there is right side closer to your left in bore size I'll give you a good deal on it if you like. 
Might take me a couple of days, it's 5deg outside and maybe 20deg in the shop currently.  I don't do much out there this time of year anymore.  I used to do porting in the basement this time of year when I had clients prepping for Daytona or the NHIS season opener. Those days are long gone though. 
Title: Re: Yamaha rd350 road racer
Post by: Hurco550 on Jan 09, 2017, 22:13:00
I'd really appreciate that shoeman! I'd really feel better about it if I had one with a few more bores left in it and a sleeve that wasn't as thin as this one. If you happened to have a descent set you'd want to part with let me know as well! I hear ya on the cold shop too. I'm burning through the propane making my little shop as workable as possible. Darned thing is even when the shop gets warm, all the tools are still almost to cold to handle still. First world problems I know lol

I don't have the article handy, but I remember dad telling me about one he read where an old privateer snowmobile racer back in the day put a mod podge motor together to be able to run in a certain class. I don't remember the exact details, but it was among the lines of a twin engine motor that he ran one jug from a 340cc motor and the other jug from a 440cc motor to fall within total cc requirements. I didn't figure it would be a huge issue on a miniscule cc miss match, but I figured I'd check with you guys first. Thanks again for all your help so far!!
Title: Re: Yamaha rd350 road racer
Post by: clem on Jan 10, 2017, 00:43:12
Check the porting also to ensure that they are both stock or the same at least. I also have an extra cylinder that I'd hook you up with if needed.

Sent from my SAMSUNG-SM-G920A using DO THE TON mobile app (http://'https://siteowners.tapatalk.com/byo/displayAndDownloadByoApp?rid=89466')

Title: Re: Yamaha rd350 road racer
Post by: Hurco550 on Jan 10, 2017, 00:50:35
Check the porting also to ensure that they are both stock or the same at least. I also have an extra cylinder that I'd hook you up with if needed.

Sent from my SAMSUNG-SM-G920A using DO THE TON mobile app (http://'https://siteowners.tapatalk.com/byo/displayAndDownloadByoApp?rid=89466')
Good call man, didn't think of that, though I'll have to look to make sure, I don't think any of the posts have any tool marks and are still factory cast.
Thanks!
Title: Re: Yamaha rd350 road racer
Post by: Shoeman on Jan 10, 2017, 08:04:28
I heard back from the fellow with the Chinese cylinders and he reports no problems, he piped it, added an electronic ignition, and ran the bike for a couple years then sold it. Used it to teach his then 13 year old son to ride too.  Now that's a dad!
Title: Re: Yamaha rd350 road racer
Post by: Hurco550 on Jan 10, 2017, 11:35:46
I heard back from the fellow with the Chinese cylinders and he reports no problems, he piped it, added an electronic ignition, and ran the bike for a couple years then sold it. Used it to teach his then 13 year old son to ride too.  Now that's a dad!
Thanks for following up with him for me! If something doesn't work out with one of you having a barrel, I'll feel better about going that route now!
Title: Re: Yamaha rd350 road racer
Post by: Tune-A-Fishİ on Jan 10, 2017, 11:43:12
its not a language as much as it is a side effect to the disease known as twostrokefluenza.

Ah an STD...  Simplified Twostroke Disorder... Nevr made the connection Mr. Obvious  ;D 
Title: Re: Yamaha rd350 road racer
Post by: jpmobius on Jan 10, 2017, 12:56:31
I wouldn't hesitate to run miss matched cylinder bores.  Maybe a good topic for discussion elsewhere, but I don't see any downside.  So what if the output on each cylinder matches or not?  Even with one cylinder with zero output - even on a twin - the consequences might be annoying, but there isn't any sort of dreadful imbalance or stress added to anything.  Of course in the extreme example of losing one cylinder entirely you lose half the power plus the power robbed by pulling along the dead cylinder, but as long as lubrication is maintained mechanically I don't see an issue.  I have to think that you would commonly see a greater difference in output per cylinder for any number of reasons than the small difference due to the slight bore difference.  After all, on most bike engines, each cylinder is basically a complete stand alone engine with separate carb, intake exhaust and ignition coil.  Build two 175cc motors as carefully as you can and you would be hard pressed to get outputs that match exactly.
Title: Re: Yamaha rd350 road racer
Post by: Hurco550 on Jan 11, 2017, 21:05:41
Got some more reading material =) thanks for the recommendation teazer!
(https://uploads.tapatalk-cdn.com/20170112/091e1cd7205a5e696c59a2e3c3485110.jpg)
Title: Re: Yamaha rd350 road racer
Post by: irk miller on Jan 11, 2017, 21:34:30
Golly, you guys sure are ringing in the technology...

(http://abcnews.go.com/images/Technology/gty_alexander_graham_bell_thg_130426_wblog.jpg)
Title: Re: Yamaha rd350 road racer
Post by: Redbird on Jan 18, 2017, 18:40:04
Done yet?
Title: Re: Yamaha rd350 road racer
Post by: Hurco550 on Jan 18, 2017, 20:11:54
Done yet?
Man I wish. I got put back on 13 hour days, so when I roll in the drive at 9:15 p.m. The wind is pretty well gone out of my sails. Also, the interceptor is up on the rack and I want it squared away by spring..... Oh and money, Im waiting on more of that too lol
Title: Re: Yamaha rd350 road racer
Post by: Redbird on Jan 19, 2017, 19:26:32
Yea, I know how it is. I average 12hr days. I don't plan much during the week because I'm generally either working or sleeping :P
Title: Re: Yamaha rd350 road racer
Post by: Hurco550 on Jan 19, 2017, 19:28:30
Yea, I know how it is. I average 12hr days. I don't plan much during the week because I'm generally either working or sleeping
I can't really complain. Working these hours allows me to take about two months off in the summer. That works for me.
Title: Re: Yamaha rd350 road racer
Post by: Hurco550 on Jan 19, 2017, 19:31:52
Also, I posted it up in that other thread, but found this cht setup that's for an ultralight aircraft. I started out looking for an old one for an arctic cat or boaski snowmobile, but they are a little hard to find in good nic, and more expensive than these are new. It will be nice to know the head temp once I actually get this thing going. Probes install under the spark plugs.
(https://uploads.tapatalk-cdn.com/20170119/0f8930df7d7f34ab249f723abc036d5c.jpg)
Title: Re: Yamaha rd350 road racer
Post by: Maritime on Jan 20, 2017, 09:03:02
That's Kool Levi, what do they cost?
Title: Re: Yamaha rd350 road racer
Post by: Hurco550 on Jan 20, 2017, 09:22:47
That's Kool Levi, what do they cost?
A hair less than $70 for the gauge and sensors to my door
Title: Re: Yamaha rd350 road racer
Post by: Maritime on Jan 20, 2017, 10:40:30
Not bad, I'll keep that in mind should I need one. The temp gauge doesn't work on the CX and I'd like something to replace it, only I'd need to know what the temp range for the heads should be on it vs the coolant temp the normal gauge reads.
Title: Re: Yamaha rd350 road racer
Post by: Hurco550 on Jan 20, 2017, 10:49:32
Not bad, I'll keep that in mind should I need one. The temp gauge doesn't work on the CX and I'd like something to replace it, only I'd need to know what the temp range for the heads should be on it vs the coolant temp the normal gauge reads.
Right. I haven't seen many people run a cht gauge on top of a liquid cooled motor. Even on an air cooled two stroke, if looking for signs of detonation, I've seen a few people argue that by the time the heat reaches the sensors, the damage is already done. In my mind this is mostly a neat addition without a huge complexity or weight penalty, as well as some way to monitor the head temps if I happen to get caught in traffic with the full fairing.
Title: Re: Yamaha rd350 road racer
Post by: Maritime on Jan 20, 2017, 10:50:58
Yep, gotcha, I kind of thought of that after I typed it. I just need to get off my ass and trace the wiring to the gauge with a multi meter and test the temp sensor and see which is buggered.
Title: Re: Yamaha rd350 road racer
Post by: Hurco550 on Jan 20, 2017, 10:54:23
Yep, gotcha, I kind of thought of that after I typed it. I just need to get off my ass and trace the wiring to the gauge with a multi meter and test the temp sensor and see which is buggered.
Yep, electrical trouble shooting is not my thing. That's one of the few parts of working on old bikes that isn't enjoyable to me. I'm lucky to have a buddy that is a forklift mechanic and his bead and butter is electrical trouble shooting
Title: Re: Yamaha rd350 road racer
Post by: jpmobius on Jan 20, 2017, 11:56:46
I've seen a few people argue that by the time the heat reaches the sensors, the damage is already done. 

I've run them on air cooled, and if you are actually watching, you can absolutely save your engine.  When you see the temp needle climbing faster than your tach, it's time to let go of the throttle!  300o to 450o+ in just a couple of seconds.
Title: Re: Yamaha rd350 road racer
Post by: Hurco550 on Jan 20, 2017, 13:00:53
I've run them on air cooled, and if you are actually watching, you can absolutely save your engine.  When you see the temp needle climbing faster than your tach, it's time to let go of the throttle!  300o to 450o+ in just a couple of seconds.

That's good to know. Did you run similar ones from an aircraft or something different?
Title: Re: Yamaha rd350 road racer
Post by: jpmobius on Jan 20, 2017, 15:44:31
This:  http://www.ebay.com/itm/VDO-Cylinder-Head-Temp-600-Degrees-Kit-/152347081170 (http://www.ebay.com/itm/VDO-Cylinder-Head-Temp-600-Degrees-Kit-/152347081170).  I used their thermocouples as well which have high temp wires and sit under the spark plug.  When I was drag racing I watched this instead of my tach a lot of the time.
(http://i.ebayimg.com/images/g/BvoAAOSwA3dYR5-v/s-l1600.jpg) 
Title: Re: Yamaha rd350 road racer
Post by: Hurco550 on Jan 20, 2017, 21:49:06
This:  http://www.ebay.com/itm/VDO-Cylinder-Head-Temp-600-Degrees-Kit-/152347081170 (http://www.ebay.com/itm/VDO-Cylinder-Head-Temp-600-Degrees-Kit-/152347081170).  I used their thermocouples as well which have high temp wires and sit under the spark plug.  When I was drag racing I watched this instead of my tach a lot of the time.
(http://i.ebayimg.com/images/g/BvoAAOSwA3dYR5-v/s-l1600.jpg)
Did you run two gauges or did that average the two cylinder temps?
Title: Re: Yamaha rd350 road racer
Post by: jpmobius on Jan 20, 2017, 22:31:43
I only ran a single gauge.  I'd swap over the thermocouple now and again but never noticed any significant difference between cylinders.  If you ran too much advance and the thing started detonating, in theory you'd have the same problem on the other cylinder as well.  I stopped using them all together after a time as the usefulness (to me at least) went fairly thin (probably have just cursed myself for saying that!), as temperatures were always pretty constant unless there was detonation in which case you got instantly soaring temps above the norm.  The thing is, such an instrument is not like a water temp gauge, as many things can start to go awry at any time down the road and the long term monitoring has value.  In the main, once you have the thing tuned, there is not much likely to cause a change.  Cylinder head temperature in general seemed as much dependent on ambient temperature as anything else once you got the thing running half way right.  I think if you want to tune to the razor's edge they are pretty useful, but on a street bike you just can't do that with any degree of safety.  Get the ignition advance where it REALLY sings one day, and it's doom the next day with no changes except the weather or time of day.  You just have to tune to some margin of safety if you want daily use.  Once you have it there, the gauge functions more like a light that tells you the thing is running - it never tells you anything useful.  However, if you are not sure about what you are doing, being able to monitor cylinder head temperature is pretty valuable - but you do have to pay attention.  If you don't, you will discover your error at nearly the same time - it will just be a lot more expensive!
Title: Re: Yamaha rd350 road racer
Post by: Shoeman on Jan 21, 2017, 08:40:04
I think if you want to tune to the razor's edge they are pretty useful, but on a street bike you just can't do that with any degree of safety.  Get the ignition advance where it REALLY sings one day, and it's doom the next day with no changes except the weather or time of day.  You just have to tune to some margin of safety if you want daily use. 

BINGO!   
Title: Re: Yamaha rd350 road racer
Post by: Sav0r on Jan 21, 2017, 10:42:14
In my opinion CHT is a pretty awful way of tuning a two stroke, as is water temp. Neither of which react quick enough to generate any meaningful feedback. They do however provide a baseline for understanding engine condition. As JMobius says, we always used ambient temperature as a factor of CHT, it's been a while but I believe we aimed for 350F plus ambient, if we got much over 500 we were too hot. Unfortunately mixture had little effect generally, other factors were more important. This wasn't for an RD, but this was for other Yamaha racing engines. On the street I doubt you'll ever see anywhere near 500F as this required sustained full throttle operation. EGT and especially Lamda are much more useful. Lambda brings some fowling issues that really aren't great for street use. So that leaves EGT. I use dual EGT's on my street RD and have had good success. That's not to say they are without issue though. I record them at 20hz and when I use them as a tuning aid I only review the data from a consistent route (my favorite twisty section of road on the way to my office) post ride. And that's the real kicker here, if you are tasked with manually reading that gauge while riding on the road you are asking for more than engine trouble, especially considering that you won't be getting any valuable readings until you really wind the thing out. Moreover, you have to establish a consistent environment to read EGT. The track is great for this, the street is much harder. I've seen a tail wind reduce the EGT reading, imagine how grade, straight length, etc. can complicate things. The good news is that used data loggers are becoming cheaper by the day, the technology from the early 2000's can often record at 200hz on several channels. The loggers I use in my RD has 8 external inputs which I use for EGT and some shock pots as well as several other channels such as ambient temp and battery voltage that are integrated. I found mine used and got a good deal.
Title: Re: Yamaha rd350 road racer
Post by: teazer on Jan 21, 2017, 13:30:20
I started with a good relatively cheap Innovate Lambda (air:fuel) gauge and then added EGT and TPS and RPM and data logger and there is no way in hell I could think about trying to read a fraction of that live on the street or on the strip. After a run, fine, but not real time.

I tried a nice set of Wetsach (SLP) triple EGT pickups and gauge, but when the wick is wound right up, there's no time to read the gauges let alone react. 


I like CHT gauges as a general guide to see if both sides (or all three in my case) are reasonably similar but I'm not sure I'd be able to react fast enough to a CHT spike (detonation) while riding hard. But as a set up tool, they have a place in the toolbox.
Title: Re: Yamaha rd350 road racer
Post by: Redbird on Jan 23, 2017, 18:38:31
I can't really complain. Working these hours allows me to take about two months off in the summer. That works for me.
Well Fuck You then!! :P
Title: Re: Yamaha rd350 road racer
Post by: Hurco550 on Jan 23, 2017, 18:40:07
Well Fuck You then!!
You mean you don't get two months off every summer? I thought that's how it worked for everyone! ;)
Title: Re: Yamaha rd350 road racer
Post by: Ply318ci on Jan 23, 2017, 19:58:59
You mean you don't get two months off every summer? I thought that's how it worked for everyone! ;)


I do and I only work 8 hours a day. But those 8 hours are spent with Jr. High kids. So kind of a trade off I guess.


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Title: Re: Yamaha rd350 road racer
Post by: Hurco550 on Jan 23, 2017, 20:03:20

I do and I only work 8 hours a day. But those 8 hours are spent with Jr. High kids. So kind of a trade off I guess.


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Definitely. I'm lucky enough to teach adult education, so I don't have to deal with all that ha
Title: Re: Yamaha rd350 road racer
Post by: Ply318ci on Jan 24, 2017, 01:21:25
Awesome. Won't lie kind of jealous.


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Title: Re: Yamaha rd350 road racer
Post by: irk miller on Jan 24, 2017, 08:10:23

I do and I only work 8 hours a day. But those 8 hours are spent with Jr. High kids. So kind of a trade off I guess.


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I couldn't do just Jr High.  My sister does, and I don't know how she survives.  I have one Jr High class and the rest is high school.  Usually one college class a semester for extra money.  The college kids are often too lazy.
Title: Re: Yamaha rd350 road racer
Post by: Tune-A-Fishİ on Jan 24, 2017, 08:26:23
I thought "Jr. High" was changed to "Middle School"
Title: Re: Yamaha rd350 road racer
Post by: Ply318ci on Jan 24, 2017, 11:09:55
I couldn't do just Jr High.  My sister does, and I don't know how she survives.  I have one Jr High class and the rest is high school.  Usually one college class a semester for extra money.  The college kids are often too lazy.

I used to teach High School and t is way better.  8th grade is about as young as I can handle teaching. Did elementary for a while to, that was rough.


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Title: Re: Yamaha rd350 road racer
Post by: Ply318ci on Jan 24, 2017, 11:10:23
I thought "Jr. High" was changed to "Middle School"

It is but I am old enough to remember it as Jr. High hard to drop old habits I guess.


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Title: Re: Yamaha rd350 road racer
Post by: Hurco550 on Jan 29, 2017, 20:47:15
Got a nice little update. Nick over at adventure co studios cut me out some decals that match the original "patina" on the old fairing. They came out perfect!

Also, Stay tuned as a recent eBay purchase will be showing up that I'm pretty excited about ;)
(https://uploads.tapatalk-cdn.com/20170130/c28e4e3cc995e26ff2dd7749780f7074.jpg)
Title: Re: Yamaha rd350 road racer
Post by: Tune-A-Fishİ on Jan 29, 2017, 20:49:16
Nice! 90?


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Title: Re: Yamaha rd350 road racer
Post by: Hurco550 on Jan 29, 2017, 20:50:45
Nice! 90?


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I was born in 90'
Title: Re: Yamaha rd350 road racer
Post by: clem on Jan 29, 2017, 21:15:11
I graduated in 91

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Title: Re: Yamaha rd350 road racer
Post by: Tune-A-Fishİ on Jan 29, 2017, 21:22:20
My son was born in 89
Title: Re: Yamaha rd350 road racer
Post by: Hurco550 on Jan 29, 2017, 21:55:03
My son was born in 89
Btw tune, I just figured out how to un block you, still haven't figured out how I did it in the first place though ha
Title: Re: Yamaha rd350 road racer
Post by: Hurco550 on Feb 02, 2017, 19:13:45
Pretty exciting update, to me anyways. The little booger is gonna be liquid cooled. I picked up a top end from a 1982 rd350lc. From what Ive read, they were never sold state side, but in Europe and Canada. I'm not pioneering anything with this mod, it's been done before a few times, but I really think it will be a neat and useful mod on this bike. It really is pretty close to a "bolt on" mod to the a.c. motor, besides sorting a radiator and probably an electric coolant pump.

(https://uploads.tapatalk-cdn.com/20170202/f431637b8d7066f8da876d80c82e1511.jpg)

I got the setup on eBay for a tick less than what a new vitos top end kit would cost. It's still stock 54mm bore and came with the pistons. I'll do some thorough measuring to see if they are still usable, but I will likely have to go one over with a fresh set of pistons.
(https://uploads.tapatalk-cdn.com/20170202/2b1d31d11acda2e6a2fe039b489015f3.jpg)

The seller didn't show the slight detonation damage on the top of one piston and head, but it is really pretty minor and doesn't cause me to much concern. The camera makes it look worse than it is, and I'm hoping it will clean up.
(https://uploads.tapatalk-cdn.com/20170202/0e6490988204af915ed03047b935cb4f.jpg)
(https://uploads.tapatalk-cdn.com/20170202/409830e3d90d1dde900bbdb59e493342.jpg)

Another thing he didn't note, and maybe due to him really not knowing, is that they have had some porting work already done to them. It looks to have been done well and nicely, but, until I sit down and measure everything against factory specs, I will not know if it's too much. Teazer, if your seeing this, heads up I may be picking your brain again soon since you were already looking into my pipe specs and pointing me in the right direction on porting of the a.c. barrels.
Looks like they did intake, exhaust and transfer port cleanup at the least, but I don't know how far they took it.
(https://uploads.tapatalk-cdn.com/20170202/1278ee123221d6513cda6ae8fe8e662d.jpg)
Title: Re: Yamaha rd350 road racer
Post by: farmer92 on Feb 02, 2017, 20:19:09
Niiiice score
Title: Re: Yamaha rd350 road racer
Post by: Tune-A-Fishİ on Feb 02, 2017, 22:51:54
Pretty exciting update, to me anyways. The little booger is gonna be liquid cooled. I picked up a top end from a 1982 rd350lc. From what Ive read, they were never sold state side, but in Europe and Canada. I'm not pioneering anything with this mod, it's been done before a few times, but I really think it will be a neat and useful mod on this bike. It really is pretty close to a "bolt on" mod to the a.c. motor, besides sorting a radiator and probably an electric coolant pump.

I have a real good EX250 radiator, even has a fan on it but could be removed

eBay images but same same chit mang  :o
(http://i.ebayimg.com/images/g/GqUAAOxyQfJTfGPy/s-l1600.jpg)
(http://i.ebayimg.com/images/g/inAAAOxycgVTfGQH/s-l1600.jpg)
Title: Re: Yamaha rd350 road racer
Post by: Hurco550 on Feb 02, 2017, 23:27:24
I have a real good EX250 radiator, even has a fan on it but could be removed

eBay images but same same chit mang  :o
(http://i.ebayimg.com/images/g/GqUAAOxyQfJTfGPy/s-l1600.jpg)
(http://i.ebayimg.com/images/g/inAAAOxycgVTfGQH/s-l1600.jpg)
Thanks man, but I think I'll go with this one. $44 shipped and the inlet and outlet are much closer to where they will need to be.

Look at this on eBay http://www.ebay.com/itm/162214043755
Title: Re: Yamaha rd350 road racer
Post by: Tune-A-Fishİ on Feb 02, 2017, 23:28:58
Aw yes, and such a deal.
Title: Re: Yamaha rd350 road racer
Post by: teazer on Feb 03, 2017, 00:49:34
In terms of porting all I can say is "we know nuuthing" in best Sergeant Shultz accent.  ;-)  That radiator is insanely cheap.  And just as I was thinking that the EX rad might be a nice cheap way to go.

The reed cages look as if they may have been opened up to take RZ350 reed blocks.  If not go with YZ85 cages.

I hope that piston is 64mm (350) and not 54mm (250) but either will work. Just not the same way.  When you get a chance to map the ports, I can tell you if they are stock or modified.  The inlets look OK but could be improved at the liner.  They are better than any RD aftermarket I have looked at so far.
Title: Re: Yamaha rd350 road racer
Post by: VonYinzer on Feb 03, 2017, 15:39:42
Thanks man, but I think I'll go with this one. $44 shipped and the inlet and outlet are much closer to where they will need to be.

Look at this on eBay http://www.ebay.com/itm/162214043755

Looks like a steal. Make sure you do a mild pressure test before running it on the bike. Not that you'll be dealing with any insane numbers down the road, but when you find deals like that there's always the chance the manufacturing isn't 100% solid. I'm sure you can find a decent fabricator around to fix up any possible failures though ;)
Title: Re: Yamaha rd350 road racer
Post by: Hurco550 on Feb 07, 2017, 22:47:41
In terms of porting all I can say is "we know nuuthing" in best Sergeant Shultz accent.  ;-)  That radiator is insanely cheap.  And just as I was thinking that the EX rad might be a nice cheap way to go.

The reed cages look as if they may have been opened up to take RZ350 reed blocks.  If not go with YZ85 cages.

I hope that piston is 64mm (350) and not 54mm (250) but either will work. Just not the same way.  When you get a chance to map the ports, I can tell you if they are stock or modified.  The inlets look OK but could be improved at the liner.  They are better than any RD aftermarket I have looked at so far.
My bad, they are indeed 64mm bores and 350 barrels. That was my mistake when typing.

The reed openings are the same as my stock ac barrels in width. I've already bought yz125 petals to replace the stock ones, but if the 85's are better, I'll go with those instead.
(https://uploads.tapatalk-cdn.com/20170208/ba6ddd7bcd8b0b64054f006924f7ffe8.jpg)
(https://uploads.tapatalk-cdn.com/20170208/9837f80a75c4d41accec566034f4df7f.jpg)
(https://uploads.tapatalk-cdn.com/20170208/3b6c7a9331c3c7d0f6c66e4860967e45.jpg)

I got some time tonight to sit down and map the ports. All dimensions for the air cooled barrels were taken from one of my un molested ac barrels, and the dimensions from both my lc barrels. The port dimensions from one lc barrel to the next were about spot on. I've read a few articles on correctly measuring transfer port dimensions at the "right" angles to get the most out of accurately figuring port time windows, but for a little greater ease, I measured straight on for the sake of comparing apples to apples. If this is not acceptable, let me know and I'll go more in depth with aligned with the angle measurements.
(https://uploads.tapatalk-cdn.com/20170208/e9058309c62868b7dfac40f095da6285.jpg)

Here is how ports were measured.
(https://uploads.tapatalk-cdn.com/20170208/0fcac48ca3fffad1ad6cd6afd1d9b953.jpg)

All comparisons from ac barrels to lc barrels.

Transfers.
(https://uploads.tapatalk-cdn.com/20170208/d4b9d122cf80f580be4080bee28826d4.jpg)

Aux port.
Widened 6.5mm
Lowered .75mm
Raised 2.5mm

Main transfer port
Widened 2mm
Floor up 2mm but same over all height

Intake
(https://uploads.tapatalk-cdn.com/20170208/cc0fa38459c1dc4ad07add32a1202f6a.jpg)

7th port
Raised 2mm
Widened 1mm

"Main port" (if that's the correct terminology)

Lower 3.1mm at top
Lower at floor 2.5mm
Widened 1.75mm

Exhausts
(https://uploads.tapatalk-cdn.com/20170208/14ed99c703d29febf84db07a7b7086b8.jpg)

Raised 2.5mm
Over all height 1mm
Widened 6mm


Here are a few pictures comparing port shapes

Ac intake(https://uploads.tapatalk-cdn.com/20170208/1f6074c833c492d213fb4dd06f458566.jpg)

Lc intake(https://uploads.tapatalk-cdn.com/20170208/04590e58f9a30a1ffbaec90419d98b68.jpg)

Ac exhaust
(https://uploads.tapatalk-cdn.com/20170208/9f3c10167ec3ed86e62cf418f48e61a7.jpg)

Lc exhaust
(https://uploads.tapatalk-cdn.com/20170208/fc3a89c485c986780357dc9d9b3dbcd6.jpg)

The other thing I'm unsure of is the state of the liner cut away of the lc barrels vs the ac barrels at the base.

Ac
(https://uploads.tapatalk-cdn.com/20170208/5086fb4052c1b9eabb5e1f0b8900875a.jpg)

Lc
(https://uploads.tapatalk-cdn.com/20170208/3e3df9176e583938000b09494dbe9f24.jpg)

From what I can tell online is that the lc barrels came this way factory.

The closer I look the better the actual porting work itself looks quality wise, especially vs the stock porting of the ac barrels. That said, I'm really hoping nothing was taken to far.

As usual, ANY advice from you gurus will be most appreciated!
Title: Re: Yamaha rd350 road racer
Post by: clem on Feb 07, 2017, 23:24:41
Curious to see what the transfers look like from the bottom on the lc.

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Title: Re: Yamaha rd350 road racer
Post by: clem on Feb 07, 2017, 23:25:13
This is a stock AC 350

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Title: Re: Yamaha rd350 road racer
Post by: clem on Feb 07, 2017, 23:25:57
This is modified.

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Title: Re: Yamaha rd350 road racer
Post by: Hurco550 on Feb 07, 2017, 23:29:43
Ac left, lc right. Don't look to be crazy

(https://uploads.tapatalk-cdn.com/20170208/45695163a32039a9acd8e00aa95243f8.jpg)
Title: Re: Yamaha rd350 road racer
Post by: teazer on Feb 08, 2017, 01:04:44
TZs of all sizes look pretty much the same as those. 
Title: Re: Yamaha rd350 road racer
Post by: Hurco550 on Feb 08, 2017, 17:29:01
That's good to know. I just know it was recessed way father than the ac barrels, but from the pics I can see online, it's about right for close to stock lc barrels
Title: Re: Yamaha rd350 road racer
Post by: teazer on Feb 09, 2017, 00:49:05
"close to stock".  Yeah.  We need to talk about that......
Title: Re: Yamaha rd350 road racer
Post by: Hurco550 on Feb 09, 2017, 20:27:22
"close to stock".  Yeah.  We need to talk about that......
Lol I meant the transfer port recess at the base being close to stock. But I guess the porting not so much ;)
Title: Re: Yamaha rd350 road racer
Post by: teazer on Feb 10, 2017, 01:17:53
You got it.  Well it is close to a stock something that's water cooled and it's a Yamaha and it runs on a road surface, so close enough for government work.
Title: Re: Yamaha rd350 road racer
Post by: teazer on Feb 10, 2017, 01:19:52
This is modified.

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Clem, did you that porting at the base of the transfers or is it an OP's picture?  Usual practice is to raise the floor (with barrel RWU) on the main port but not the rear port.  That one looks like it's raised on both. 
Title: Re: Yamaha rd350 road racer
Post by: clem on Feb 10, 2017, 10:24:50
Teazer, a guru down in Florida is porting those for my bike.

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Title: Re: Yamaha rd350 road racer
Post by: Hurco550 on Feb 10, 2017, 18:09:27
Teazer, a guru down in Florida is porting those for my bike.

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Lyn garland?
Title: Re: Yamaha rd350 road racer
Post by: clem on Feb 10, 2017, 22:59:11
Lyn is in Georgia.  He did do the crank but he doesn't do porting. It's actually Chuck Q. Both super nice guys.

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Title: Re: Yamaha rd350 road racer
Post by: teazer on Feb 11, 2017, 00:32:56
Two very helpful and knowledgeable guys for sure.  I have not had Chuck do any work for me but I have seen his work (or photos of it) and it's excellent.  Both have great reputations.

That would explain the scribe marks and engineer's blue.  Looking at that picture again, I see that in fact the main transfer is being raised more than the other.

Carry on.. :-)
Title: Re: Yamaha rd350 road racer
Post by: Hurco550 on Feb 12, 2017, 14:48:54
Lyn is in Georgia.  He did do the crank but he doesn't do porting. It's actually Chuck Q. Both super nice guys.

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I've never personally spoke with either, but I've heard both of their names before, equally held in high regard in the Yamaha two stroke world
Title: Re: Yamaha rd350 road racer
Post by: irk miller on Feb 12, 2017, 15:44:44
Lyn is just south of Atlanta, a couple of hours from me and about the same for your wife's family.  I wonder if he's worth a visit the next time your down there.
Title: Re: Yamaha rd350 road racer
Post by: Hurco550 on Feb 12, 2017, 19:38:48
Lyn is just south of Atlanta, a couple of hours from me and about the same for your wife's family.  I wonder if he's worth a visit the next time your down there.
Hmmm, I may have to contact him. I'm always looking for things to do while I'm down that way
Title: Re: Yamaha rd350 Road Racer Liquid Cooled!!
Post by: Hurco550 on Apr 25, 2017, 21:38:17
If anyone is still watching, this project is still going, just slowly. I've been heavily distracted by the interceptor which is now being buttoned up.

I bought a used crank from a guy over on 2 stroke world and it showed up today. I'm going to put it up on the inspection stand and check for run out against Yamaha spec. If it's good I'm going to run it. The bearings all feel great, and it has tz slotted big end rods, as well as a tz needle bearing on the alternator side. I may just replace the outside two bearings though to be on the safe side with the helical cut drive gear as teazer pointed out.
(https://uploads.tapatalk-cdn.com/20170426/6afec944a4597b697c4d68400c2a7480.jpg)(https://uploads.tapatalk-cdn.com/20170426/5064898ea4bc665e4b443249b8a414ca.jpg)

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Title: Re: Yamaha rd350 Road Racer Liquid Cooled!!
Post by: clem on Apr 25, 2017, 22:37:46
Nice. You planning on running the stock ignition?

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Title: Re: Yamaha rd350 Road Racer Liquid Cooled!!
Post by: Hurco550 on Apr 25, 2017, 22:46:15
Nice. You planning on running the stock ignition?

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Nope, I have a full mzb cdi setup for it.


(http://uploads.tapatalk-cdn.com/20160912/f4030abf8ce2953d3fd5eb5c7567a3ac.jpg)

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Title: Re: Yamaha rd350 Road Racer Liquid Cooled!!
Post by: clem on Apr 26, 2017, 08:37:43
Awesome.  They are cheaper than when I bought mine. Very reliable and now you can get them with multiple ignition curves.

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Title: Re: Yamaha rd350 Road Racer Liquid Cooled!!
Post by: Hurco550 on Apr 26, 2017, 08:52:58
Awesome.  They are cheaper than when I bought mine. Very reliable and now you can get them with multiple ignition curves.

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I bought mine about a year ago I'm guessing. The only bad thing I've heard is that it can be a bit of a pain to set the timing, but once it is set it doesn't wear and change like points

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Title: Re: Yamaha rd350 Road Racer Liquid Cooled!!
Post by: JSJamboree on Apr 26, 2017, 10:57:24
I bought mine about a year ago I'm guessing. The only bad thing I've heard is that it can be a bit of a pain to set the timing, but once it is set it doesn't wear and change like points

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Its what im running on my RD. The hardest part is getting a dial indicator with a long extension so you can get it to your cylinder to find TDC.  I managed to nail mine first try so im sure you can get it.
Title: Re: Yamaha rd350 Road Racer Liquid Cooled!!
Post by: TranceMachineVienna on Apr 26, 2017, 12:51:25
There´s a special dial gauge set on yambits with an adapter especially fit to clear with the fins...i think its 50 squid.
Title: Re: Yamaha rd350 Road Racer Liquid Cooled!!
Post by: clem on Apr 26, 2017, 13:26:20
McMaster Carr has them. I put a setup together on the cheap. You'll dig it Levi. I'm thinking about buying the newer edition, put that on the 350 and use the static one on the Daytona. We'll see since the Daytona is becoming a money pit. 😟

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Title: Re: Yamaha rd350 Road Racer Liquid Cooled!!
Post by: clem on Apr 26, 2017, 13:31:49
The only dificulty that I had was getting the rotor to not pull itself before I could lock it down. It's a damn strong magnet and right as it would be starting to seat it would turn itself with the magnet. It only took a couple of tries to get the hang of putting on and keeping it still before tightening it down. I should mention that I did not use the keyway. HVC sets theirs up to use that but I picked mine up from economy cycle. I'm sure Jordan can testify that once it's on and set, it's done!

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Title: Re: Yamaha rd350 Road Racer Liquid Cooled!!
Post by: Hurco550 on May 04, 2017, 15:56:15
Finally got the ardee back up on the stand, and the lc barrels fitted for mockup. I gotta get the pipes mounted before the radiator, then the radiator before the fairing and the list goes on. Been chatting with teazer and he looked at my pipes. With the port timing where it is I need to take about 5" outta the head pipe, which if I can do it right, will make them tuck under better for fairing fittment ect.
(https://uploads.tapatalk-cdn.com/20170504/1af7ca264c85c2568b4a475773321aa0.jpg)(https://uploads.tapatalk-cdn.com/20170504/cd929cd903c47e8e114f1fc9c2597f67.jpg)(https://uploads.tapatalk-cdn.com/20170504/80f01b10c776037f2d04923944e351eb.jpg)(https://uploads.tapatalk-cdn.com/20170504/67feb757d784a4d48ea2a41953e09781.jpg)

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Title: Re: Yamaha rd350 Road Racer Liquid Cooled!!
Post by: teazer on May 04, 2017, 23:25:19
If it were mine, I would probably get the bike running with the pipes as they are and get a sense of how it runs.  Then pull out whatever length can easily be removed from the header and try it again and see if you like where the development is going.   If it's going well and you want to take more out, go ahead and pie cut the header to get some more out of it.

Just because the software says that would be best, you are the guy riding it and it's you that has to like the power characteristics. If it gets to be too much top end and not enough down low for the way you ride, that's not a lot of fun, so take it in steps.
Title: Re: Yamaha rd350 Road Racer Liquid Cooled!!
Post by: kar1zma on Jun 01, 2018, 11:27:41
any update on this project
Title: Re: Yamaha rd350 Road Racer Liquid Cooled!!
Post by: irk miller on Jun 04, 2018, 16:40:07
There sure as hell needs to be.
Title: Re: Yamaha rd350 Road Racer Liquid Cooled!!
Post by: der_nanno on Jun 06, 2018, 03:37:44
Yup. The world needs more ratty-tatty-two-stroke-racebikes.  8)
Title: Re: Yamaha rd350 Road Racer Liquid Cooled!!
Post by: Hurco550 on Jun 06, 2018, 12:55:25
Its been back burnered, but not forgotten. In fact, I just moved it into short term storage at my uncles place in preparation to move to our new house lol. Ive been distracted by the impending move to the new house, our first baby on the way, dual sports and BMW airheads. This one will happen still, just more of a long term project.