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Blood Sweat Tears and Grease => Projects => Restorations => Topic started by: AimlessMoto on May 25, 2017, 01:24:29

Title: RD400 - Back from the Dead
Post by: AimlessMoto on May 25, 2017, 01:24:29
For a mere $200 of my dollars, I was able to snag this gem of 70's blue-smoke from under a pine tree... It had been parked, under a tarp, for over 10-years.

It's 100% there, engine turns over and has good compression, and although it was a home for chipmunks (dear God the smell) it appears all hoses, rubber, and wires are in-tact.

I have had a lot of experience with 2 strokes, and know some of these old "street bikes" of the 70's can catch a fair price if taken care of. SO, I'm going to do a "light" restoration on this one.

- Buff out the chrome.
- Rid the thing of piss.
- Clean up the tank.
- Paint the frame.
- Restore all systems to factory.
- New tires.
- Make it smoke.

I want to avoid painting the tins... but there are some rusty bits on them... probably impossible to find a touch-up that will blend.

Pics are as-picked... then after a pressure-wash.

Title: Re: RD400 - Back from the Dead
Post by: advCo on May 25, 2017, 02:19:56
Nice buy! Not looking so bad after that pressure wash either.
Title: Re: RD400 - Back from the Dead
Post by: interceptor on May 25, 2017, 06:57:16
Sweet!  I hope it doesn't take much to get going.  Love those bikes   :) 
Title: Re: RD400 - Back from the Dead
Post by: JustinLonghorn on May 25, 2017, 08:00:33
Very nice! I love the green.
Title: Re: RD400 - Back from the Dead
Post by: SONIC. on May 25, 2017, 08:58:21
Score!
Title: Re: RD400 - Back from the Dead
Post by: Maritime on May 25, 2017, 11:50:31
Nice. sign me up to watch.
Title: Re: RD400 - Back from the Dead
Post by: VonYinzer on May 25, 2017, 14:50:25
I'll give ya $300 for it as is ;)

Great find! Looking forward to seeing it back on the road!
Title: Re: RD400 - Back from the Dead
Post by: cbrianroll on May 25, 2017, 16:17:44
Awesome find there man!
Title: Re: RD400 - Back from the Dead
Post by: goldy on May 27, 2017, 08:45:40
Wow, that's a NICE bike!  And the price was right too! That's in such decent condition (all things considered), I'm sure just a thorough detailing and a bit of maintenance/ repair would cut the mustard. It would look great as a 'survivor', although I myself have a tendency to lean toward the restoration side of the argument. Ether way, I'll be peeking in now and then, please keep us posted!
Title: Re: RD400 - Back from the Dead
Post by: AimlessMoto on May 30, 2017, 10:25:20
I agree, Goldy. My head says get it running and keep it as is, my heart is screaming "BARE FRAME! CALL THE POWDER COATERS! BYU ALL THE GASKETS!"

Lol... but I think Im going to meet it half way. Or at least attack the build in stages.

Stage 1: Cleaning, mechanicals, maintenance, get it rideable.
Stage 2: Restore chassis, engine, brake and suspension components.
Stage 3: Restore paint, and hunt down NOS parts dow  to nuts and bolts to keep it 100% stock.

So far Ive started tearing it down... little rust on the tinwork, and in the tank, but not horrible. The wiring has been chewed, and there is a LOT of shit to clean up. The paint has been eaten clean through in some areas.

Carbs are stuck. Will have to boil them. Brakes are dragging, and front is bone dry. Some dings and dents on the gauges and mounting brackets. Looks like someone tried to repair it with bondo.

Points look new. Pump looks new. Someone definitely took the covers off a few times... stripped 3 of the old Japanese screws. Tempted to swap for allan heads, but dont want to wreck originality.

More to come... just the tip of the iceberg.

Title: Re: RD400 - Back from the Dead
Post by: Ryan Stecken on May 30, 2017, 11:39:25
Subscribed!
make sure you exchange the rotten crank seals too!
Title: Re: RD400 - Back from the Dead
Post by: AimlessMoto on May 30, 2017, 13:25:53
Subscribed!
make sure you exchange the rotten crank seals too!

Purchased and on the way!  ;)
Title: Re: RD400 - Back from the Dead
Post by: AimlessMoto on Jun 04, 2017, 03:07:45
As always... we begin with the carbs. Popped them off, and gave them a rigorous boil in lemon juice... So clean you could eat off'em now.

Popped off the reed valves... seems the reeds are a bit slack. Might be normal, will have to check the manual. Then I took the heads off. To my surprise, the pistons look fairly new... both have different gaskets, and both have different numbers stamped on them... could be one is OE? I cant tell. 

Some minor concerns started bubbling up once the motor was coming apart... mainly, the pistons are loose in the cylinders... front to back and side to side... about .010 to .020...

Im going to pop the rings off and check them in the bores... also going to read up on the clearances in the manual... hopefully all is well ... ?
Title: Re: RD400 - Back from the Dead
Post by: teazer on Jun 04, 2017, 12:17:47
Those are 1mm oversized Wiseco pistons with very few miles on them and rocking at the top is not an issue. Pistons have a taper and are smaller at the top than the bottom and smaller again between the ring lands.  Check the clearance between bottom of the piston skirt and the bore.  Wiseco use different clearance than stock cast pistons.

Reeds tend to do that so get a set of new petals. Call John at Economy Cycle and see what he has for a stock motor. There are a few choices.  The only ones I don't like are Boyesen.

With barrels off, you could go ahead and port it and have the heads machined.  Chuck Quinzler in FL can advise you what he would do to keep it stock but better in terms of porting.  His work is really first class. There are others who can do porting work too.
Title: Re: RD400 - Back from the Dead
Post by: AimlessMoto on Jun 04, 2017, 13:19:17
Those are 1mm oversized Wiseco pistons with very few miles on them and rocking at the top is not an issue. Pistons have a taper and are smaller at the top than the bottom and smaller again between the ring lands.  Check the clearance between bottom of the piston skirt and the bore.  Wiseco use different clearance than stock cast pistons.

Reeds tend to do that so get a set of new petals. Call John at Economy Cycle and see what he has for a stock motor. There are a few choices.  The only ones I don't like are Boyesen.

With barrels off, you could go ahead and port it and have the heads machined.  Chuck Quinzler in FL can advise you what he would do to keep it stock but better in terms of porting.  His work is really first class. There are others who can do porting work too.

Thanks! I can just now see the "1.00mm" stamp!

Can I check the clearance as I would by the manual?

Stock specs:
Piston ring in groove should be <.05mm gap.
Ring end gap in bore should be 0.3-0.5mm.
Cylinder bore clearance piston at the skirt with the piston 3/4" down from TDC should be <.035mm.

Thats pretty much all I have to go by. Are there Wiseco specs on their site?
Title: Re: RD400 - Back from the Dead
Post by: AimlessMoto on Jun 04, 2017, 14:20:35
Nevermind... found this:
Title: Re: RD400 - Back from the Dead
Post by: teazer on Jun 04, 2017, 16:55:02
That's teh place to start.  BTW, how did you clean the carbs?  What I am really asking is did you check each and every passageway by blasting cleaner through it and comparing both carbs?  A dip and boil does not always clean out the tiny drillings causing people to lose their minds thinking the carbs are perfect and sometimes they are not.
Title: Re: RD400 - Back from the Dead
Post by: AimlessMoto on Jun 04, 2017, 17:20:47
Of course! Compressed air, cleaner, and wire.
Title: Re: RD400 - Back from the Dead
Post by: AimlessMoto on Jun 05, 2017, 23:50:19
Potential bad news... Took everything apart... here are my measurements :

Left Cyl:
Bore - 65.05mm
Cyl Clearance - .005"
Top Ring Gap - .040"
Bottom Ring Gap -.040"

Right Cyl:
Bore - 64.72mm
Cyl Clearance - .003"
Top Ring Gap - .017"
Bottom Ring Gap- .018"

So the right is on the cusp, and the left is bunk... probably a lean condition on the left side, or a terrible machining job.

Anyhoo... Wiseco makes 1.50 and 2.00 over bore kits... $300, plus machine shop work... this bike is getting expensive!

Looks like they only have the 2.00 in stock, too... may be the last ride for this pony...
Title: Re: RD400 - Back from the Dead
Post by: teazer on Jun 06, 2017, 00:02:41
I would get a set of rings, check the gaps and as long as they are big enough put it back together. The difference in bores is a bit wider than I would expect, but not the end of the road.  Those numbers are not perfect, but probably closer than many bikes on teh street.  Cold it may rattle a little but it's a two stroke, they are supposed to make noise.
Title: Re: RD400 - Back from the Dead
Post by: AimlessMoto on Jun 06, 2017, 00:17:32
Really? I guess so. Just to get it running and riding at least. Could always fix it later if the need is there. I also did a little research sinse posting and found 86-09 Banshee pistons are a direct fit... Fast From The Past sells Wossner piston kits at 65.5mm for $99 a cylinder. Specific to the RD400.

At least I know there's options... but I'll call up wiseco and see about some new rings for now.
Title: Re: RD400 - Back from the Dead
Post by: clem on Jun 06, 2017, 11:18:12
Go and check out economy cycle. Pro x, wiesco, etc. They are out there. To use banshee piston you will need to file down the skirt on the intake side but that's no big deal.

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Title: Re: RD400 - Back from the Dead
Post by: AimlessMoto on Jun 06, 2017, 17:00:31
I just bought a better bore-gauge... going to double check when that comes in. Then I can bring them to a machine shop and see what they recommend...

I found a 65.25mm Wiseco set for the Banshee for $170 shipped. And Amazon has 65.25 or .50 Pro-X for $70 a piston kit.

Not so bad after all. Hopefully I can get away with the 65.25mm overbore.
Title: Re: RD400 - Back from the Dead
Post by: AimlessMoto on Jun 06, 2017, 19:17:48
Got an appointment for Monday to meet up with an old-timer machinist. Should be a quick flip.
Title: Re: RD400 - Back from the Dead
Post by: AimlessMoto on Jun 07, 2017, 00:18:25
Gave it a legit attack tonight.... was able to borrow some better tools. Checked each cyl 9 ways, each piston 3, and re checked the rings. As you can see in the photo, the bottom of the left cyl is 65.16mm... but the top isnt too bad. This was throwing off my shim measurement with the piston 3/4 of an inch down in the bore.

BUT if you look at the top right... I tried the left rings in the right bore, and got .002" larger than the right ones... so not only are they gapped wide, but the cylinder is also large enough to double that measurement.

Maybe new rings will suffice? But 65.16 means im getting aweful close to 65.25 anyway...

Still bringing it to the machinist... but should I just bite the bullett and order pistons anyway?

My gut says yes... and so does my OCD. Lol.
Title: Re: RD400 - Back from the Dead
Post by: teazer on Jun 07, 2017, 02:04:31
If your machinist is an auto machinist, he will probably have a really good bore gauge and will be able to advise what needs to be done. If teh budget will stand it, get a pair of pistons.  He can tell you if it will clean up at 65.25 or if he needs to go to 65.5.  Sounds like it's close to needing a rebore and hone and if the crank is getting new seals maybe a good idea to go with fresh bores that are not tapered and out of round.
Title: Re: RD400 - Back from the Dead
Post by: AimlessMoto on Jun 07, 2017, 12:32:17
Thats the thing. I was hoping to get the pistons before going to the shop. Then he can just match them.

I think im just going to buy the 65.25s from Pro-x because theyre cheaper. If I need to, I can return them through amazon. If he tells me he needs 65.50s, ill return them and spend the extra on wisecos.
Title: Re: RD400 - Back from the Dead
Post by: JSJamboree on Jun 07, 2017, 14:07:00
I saw RD heads in the uploaded pics feed, had to stop in and see whats going on in here
Title: Re: RD400 - Back from the Dead
Post by: AimlessMoto on Jun 07, 2017, 16:40:22
I saw RD heads in the uploaded pics feed, had to stop in and see whats going on in here

Lol, just looked through your RD build. Amazing work! You live in VT? Im in MA.
Title: Re: RD400 - Back from the Dead
Post by: Maritime on Jun 07, 2017, 16:42:22
JSJamboree is one of the weird Indy kids, but I see how you would think he's in VT with Stowe's brewing avatar, happens to be his last name ;D
Title: Re: RD400 - Back from the Dead
Post by: AimlessMoto on Jun 07, 2017, 17:23:37
That and in his RD project it shows a VT license plate... hah.
Title: Re: RD400 - Back from the Dead
Post by: JSJamboree on Jun 07, 2017, 17:35:05
That and in his RD project it shows a VT license plate... hah.

No, its just a way to get titles for non titled bikes.  Get a registration in VT (They allow out of state registration and dont issue titles), so then you can take that registration to the local BMV and get a title for it.  Its backwards as shit, but gotta do what you gotta do
Title: Re: RD400 - Back from the Dead
Post by: AimlessMoto on Jun 07, 2017, 20:58:19
In MA they do that too. I can title any bike before 1989 no questions asked.
Title: Re: RD400 - Back from the Dead
Post by: JSJamboree on Jun 07, 2017, 22:16:39
In MA they do that too. I can title any bike before 1989 no questions asked.

But do they let someone who doesn't have residence in the state do it? Indiana has gotten extremely strict.


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Title: Re: RD400 - Back from the Dead
Post by: clem on Jun 07, 2017, 22:42:14
Why not just send those cylinders to bore tech in Ohio? They specialize in vintage stuff, 2 stroke stuff and vintage race stuff. They can bore and provide piston brands of your choice. I'd be weary of handing off vintage 2 stroke stuff to a machinist. I'm not saying that he isn't great at what he does but I'd like the peace of mind that it is correctly done for that particular motorcycle. It's only $65-70 a hole plus shipping and they have a very quick turn around. They won't collect dust on a shelf.

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Title: Re: RD400 - Back from the Dead
Post by: JSJamboree on Jun 08, 2017, 10:53:23
Why not just send those cylinders to bore tech in Ohio? They specialize in vintage stuff, 2 stroke stuff and vintage race stuff. They can bore and provide piston brands of your choice. I'd be weary of handing off vintage 2 stroke stuff to a machinist. I'm not saying that he isn't great at what he does but I'd like the peace of mind that it is correctly done for that particular motorcycle. It's only $65-70 a hole plus shipping and they have a very quick turn around. They won't collect dust on a shelf.

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Thats pricy
Title: Re: RD400 - Back from the Dead
Post by: clem on Jun 08, 2017, 12:20:28
What's the going rate in your area?

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Title: Re: RD400 - Back from the Dead
Post by: farmer92 on Jun 08, 2017, 12:36:32
50 a hole up here in kanukistan
So like 35 USD


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Title: Re: RD400 - Back from the Dead
Post by: AimlessMoto on Jun 09, 2017, 00:40:26
Things are getting serious...

Rolling chassis completely cleaned and degreased. Engine ready to be halved. Another go with my new bore gage found the left cyl is .16mm over from top to bottom... the right is dead-nuts 65mm. Still gonna rebore.

Gotta play with the electrical too. Lots to clean up!
Title: Re: RD400 - Back from the Dead
Post by: Bubba1982 on Jun 09, 2017, 13:31:52
Great build diary, will keep an eye on this.

What's the process with boiling gunked up carbs in lemon juice, are there any don'ts when doing this? Time/temperature etc?


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Title: Re: RD400 - Back from the Dead
Post by: Maritime on Jun 09, 2017, 13:46:33
Too long and they can get damaged from the acid in the juice but I suspect that would be if you left them overnight. I used regular pinesol on the Virago carbs and just put a sander on the container and let it run an hour, rinsed em, blew compressed air through all the openings and they were clean as a whistle. I put all the brass in a little container with carb cleaner and ductaped that to the sander shook that for an hour and again came out clean as a whistle.  The little container was glass and I could see the dirt coming out of the jets etc. was pretty neat. I did the same on 2 other small engine carbs for a tiller and mower and worked great as well.
Title: Re: RD400 - Back from the Dead
Post by: AimlessMoto on Jun 09, 2017, 14:28:47
Great build diary, will keep an eye on this.

What's the process with boiling gunked up carbs in lemon juice, are there any don'ts when doing this? Time/temperature etc?


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50/50 lemon juice and water. Get it boiling. Dunk in the carb for about 20 mins. Remove and soak in soapy water (dawn dish soap).

Blow it out with compressed air. Any remaining gunk can be cleaned out with carb cleaner.
Title: Re: RD400 - Back from the Dead
Post by: Bubba1982 on Jun 09, 2017, 15:44:15
50/50 lemon juice and water. Get it boiling. Dunk in the carb for about 20 mins. Remove and soak in soapy water (dawn dish soap).

Blow it out with compressed air. Any remaining gunk can be cleaned out with carb cleaner.

Great thanks, will give this a try!! Got a really caked up carb off my SR250 that needs a deep clean.


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Title: Re: RD400 - Back from the Dead
Post by: AimlessMoto on Jun 09, 2017, 15:47:46
The ProX pistons came in! Quickly unwrapped and began the process of de-tanging. Came out alright... really have to clean my files now... lol.

All boxed up ready for the machine shop... hope they can get the gap to .0014-.0016"...
Title: Re: RD400 - Back from the Dead
Post by: CrabsAndCylinders on Jun 09, 2017, 19:30:28
Too long and they can get damaged from the acid in the juice but I suspect that would be if you left them overnight. I used regular pinesol on the Virago carbs and just put a sander on the container and let it run an hour, rinsed em, blew compressed air through all the openings and they were clean as a whistle. I put all the brass in a little container with carb cleaner and ductaped that to the sander shook that for an hour and again came out clean as a whistle.  The little container was glass and I could see the dirt coming out of the jets etc. was pretty neat. I did the same on 2 other small engine carbs for a tiller and mower and worked great as well.

I'm going to try that sander trick!
Title: Re: RD400 - Back from the Dead
Post by: AimlessMoto on Jun 09, 2017, 21:54:42
I'm going to try that sander trick!

Sounds like Ichiban Moto foolery to me... lol.
Title: Re: RD400 - Back from the Dead
Post by: farmer92 on Jun 10, 2017, 00:08:28
Those pistons look real good there man,
And +1 for the pine sol bath, just not in the house unless you like the scent haha



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Title: Re: RD400 - Back from the Dead
Post by: AimlessMoto on Jun 10, 2017, 22:46:28
Was able to cut and file the new YZ85 reeds to fit the cages. Metal ones were slightly bent and probably original..  The fiber should last longer and if they fail sbouldnt grenade the new top end. Also, de-carboned the heads and gave them a polish. Nothing fancy, just enough to hinder carbon buildup for a while 
Title: Re: RD400 - Back from the Dead
Post by: jpmobius on Jun 11, 2017, 12:36:53
Be sure to flatten out the sealing surface.  Sheet of #400 or #600 wet or dry sandpaper (wet) on a piece of glass works great.  Mark with machinists blue or a sharpie, and lightly grind with a figure 8 motion until the marks disappear.  I glue my head gaskets with copper coat.  Don't over torque, and re-torque after the first two heat cycles!!
Title: Re: RD400 - Back from the Dead
Post by: AimlessMoto on Jun 11, 2017, 15:15:06
Do you use the copper coat with or in place of the actual gasket?
Title: Re: RD400 - Back from the Dead
Post by: jpmobius on Jun 12, 2017, 10:59:17
With the factory copper gaskets.  I give them a medium cote and let them dry or mostly dry, and then a light spray just before I assemble the heads.
Title: Re: RD400 - Back from the Dead
Post by: Maritime on Jun 12, 2017, 11:07:22
Those pistons look real good there man,
And +1 for the pine sol bath, just not in the house unless you like the scent haha



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LOL I spilled it in the basement and had pinesol smell for a week.
Title: Re: RD400 - Back from the Dead
Post by: clem on Jun 12, 2017, 11:57:24
I was given the recommendation to anneal the head gaskets on my 350. I do have it setup to run RD400 gaskets to correct squish so I don't know if it'll work the same. I rechecked after a few miles and the torque was still good. Levi put the o ring mod on his so that can be an option also.

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Title: Re: RD400 - Back from the Dead
Post by: jpmobius on Jun 12, 2017, 12:46:20
O ring is definitely the hot ticket, but the 400 gaskets work fine.  The 350 gaskets are hard to seal.  Definitely anneal them if not brand new.  Any copper gasket can be reused indefinitely by annealing.  It is simple to do.  Clean the gasket first and then holding it with a pair of pliers, heat it up with a propane torch.  The gasket will turn blue as it gets hot enough.  Heat around the surface until tho whole thing sees the color change and then quench it in water.  It should be nice and soft after that. 
Title: Re: RD400 - Back from the Dead
Post by: JSJamboree on Jun 12, 2017, 12:53:20
O ring is definitely the hot ticket, but the 400 gaskets work fine.  The 350 gaskets are hard to seal.  Definitely anneal them if not brand new.  Any copper gasket can be reused indefinitely by annealing.  It is simple to do.  Clean the gasket first and then holding it with a pair of pliers, heat it up with a propane torch.  The gasket will turn blue as it gets hot enough.  Heat around the surface until tho whole thing sees the color change and then quench it in water.  It should be nice and soft after that. 

I had never heard that, I just used the copper coat on my 350. sprayed the gaskets and the seats on the head/jugs, when really tacky put them together.  Basically works like spray adhesive except for copper.  If I pull the heads again I might look into going o-ring.  Havent had issues with the stockers yet though
Title: Re: RD400 - Back from the Dead
Post by: AimlessMoto on Jun 12, 2017, 19:01:41
Dropped off the jugs and pistons this afternoon. Have a good feeling on this guy. Should be done for Friday.

I got the chance to glass bead everything before we went... came out ok. Ports are all clean at least. Ready for paint once they come back.

Still going to deck the heads on some 800g and glass... will wait until after paint.

Title: Re: RD400 - Back from the Dead
Post by: JSJamboree on Jun 12, 2017, 20:04:17
I did glass bead on the heads, then painted them with ceramic paint.  The paint flaked off, didn't have good enough surface to stick.  With glass it puts a sort of polish to the metal.  I had to sand blast the rest of the paint off and after the sand it stuck like a champ.  Not sure if that was the issue for sure, but just thought I would put it out there. 
Title: Re: RD400 - Back from the Dead
Post by: AimlessMoto on Jun 12, 2017, 21:14:47
Thanks! These have a definite etch, itll shred a papertowel rubbed on the flat.
Title: Re: RD400 - Back from the Dead
Post by: jpmobius on Jun 12, 2017, 21:36:02
Glass beading is usually great for paint.  You have to do a very thorough job of cleaning your parts after though as it leaves a pretty tenacious dust film especially if the beads are worn.  Another thing I see often enough is not thoroughly cleaning and de-greasing the parts first.  While blasting with any media will clean off dirt and grease, it also just moves a lot of it around and really makes removing the contaminates later much harder.  Much like sanding to prep for paint, you absolutely have to super clean the surface first or you end up grinding into the sanding scratches the contaminates that would have been easy to remove first.  I clean everything with a very strong degreaser and then again with detergent and hot water.  Blast with air to dry and they are ready to glass bead.  This is great for not contaminating the beads, and there is no chance of grinding any grease or silicone into the part which will repel paint.  Unfortunately they need another cleaning in detergent after to remove the glass beading debris.  If it is engine parts, you want to really clean them regardless as the glass beads are pretty unfriendly to engine innards.  I have a kitchen dishwasher for the final pass - the super hot water does a very thorough job - though if you don't have one in the shop I reckon most lads will have a bit of trouble getting permission from the boss!  Even if you sandblast, you ought to thoroughly clean the parts with detergent before paint.
Title: Re: RD400 - Back from the Dead
Post by: AimlessMoto on Jun 13, 2017, 07:37:42
The heads and jugs were soaked in degreaser, brushed, soaked and scrubbed in detergent, then glass beaded, and then hit with a compressor to remove 90% of the debris...

Once the jugs are back from the shop and I have the chance to deck the heads, i will repeat the degreaser/detergent cleanings... then hit everything with hi-temp primer and bake the parts at 350 for 20 minutes.

Then paint black with epoxy.
Title: Re: RD400 - Back from the Dead
Post by: jpmobius on Jun 13, 2017, 11:39:47
Well that ought to do it!  I like thin coatings on air cooled heads and cylinders.  Been using Plasticoat ceramic engine paint for a while now and recommend it.  No primer and bake for 1 hour at 180 F.  Definitely not as tough as epoxy, but very good and I believe the cooling properties are much better.  The right black has better heat dissipation than bare aluminum, but it does not take much to become more of an insulator.  Likely you'd have to lay it on fairly heavy to be a factor, but brings up another issue.  If you ever want to refinish the heads again, that epoxy likely will be very hard to remove!
Title: Re: RD400 - Back from the Dead
Post by: AimlessMoto on Jun 13, 2017, 12:23:32
That's what I'm hoping for! I'm hoping for durability and longevity out of these parts... it's going to be hard enough to polish-back the fins once the paint cures, haha.
Title: Re: RD400 - Back from the Dead
Post by: JSJamboree on Jun 13, 2017, 14:34:20
This is what I used on my heads/jugs turned out really nice.  I have spilt enough fuel on them to say they are fuel resistant.

http://www.eastwood.com/eastwood-ceramic-engine-paint-universal-gloss-black-quart.html

(http://www.dotheton.com/forum/index.php?action=dlattach;topic=49567.0;attach=129749;image)

(http://www.dotheton.com/forum/index.php?action=dlattach;topic=49567.0;attach=129750;image)


Title: Re: RD400 - Back from the Dead
Post by: AimlessMoto on Jun 13, 2017, 20:03:45
Those look fantastic!
Title: Re: RD400 - Back from the Dead
Post by: AimlessMoto on Jun 15, 2017, 01:22:13
Polished up the chrome tonight.
Title: Re: RD400 - Back from the Dead
Post by: AimlessMoto on Jun 17, 2017, 19:45:04
Pulled all my hardware from the tub of evaporust. Wow... minor scrubbing needed on some of the more worse-off parts... but the end result is great!

Really pleased with the shocks.
Title: Re: RD400 - Back from the Dead
Post by: Maritime on Jun 17, 2017, 20:11:53
Nice. Those look great.
Title: Re: RD400 - Back from the Dead
Post by: jpmobius on Jun 17, 2017, 21:05:16
Keep in mind that Evapo-Rust also removes the cadmium plating on all that hardware (obviously the chrome is fine) so you need to either re-plate or paint everything.  It is certainly possible that some or even much of the plating is still there, but the parts will now rust very quickly where they are unprotected.  The majority of the bolts on an RD are common standard sizes that you can replace with stainless.
 Most of the applications are fine for stainless from a structural perspective so you don't have to worry about strength.  If you are really particular, even the JIS ( the old Japanese Industrial Standard) sidecover bolts (look like Phillips head) can be had in stainless.  You have some very nice parts there - you're going to have a very nice bike when you are done!
Title: Re: RD400 - Back from the Dead
Post by: AimlessMoto on Jun 18, 2017, 08:44:37
Yup! Doing a DIY zinc plating on the bits with no chrome on them. The clutch cover will use stainless allens as its what I prefer.
Title: Re: RD400 - Back from the Dead
Post by: CrabsAndCylinders on Jun 18, 2017, 15:22:34
Yup! Doing a DIY zinc plating on the bits with no chrome on them. The clutch cover will use stainless allens as its what I prefer.

What  zinc kit are you using to do this?
Title: Re: RD400 - Back from the Dead
Post by: AimlessMoto on Jun 18, 2017, 21:01:19
Home made... zinc flashing, old 6v battery charger, distilled vinegar and epsom salts... all you need. I use 6v to avoid worrying about amperage. Typically a 12v charger on 2a is the norm.
Title: Re: RD400 - Back from the Dead
Post by: CrabsAndCylinders on Jun 19, 2017, 03:01:15
Home made... zinc flashing, old 6v battery charger, distilled vinegar and epsom salts... all you need. I use 6v to avoid worrying about amperage. Typically a 12v charger on 2a is the norm.

Thanks, I would like to try that.
Title: Re: RD400 - Back from the Dead
Post by: advCo on Jun 19, 2017, 04:34:05
Home made... zinc flashing, old 6v battery charger, distilled vinegar and epsom salts... all you need. I use 6v to avoid worrying about amperage. Typically a 12v charger on 2a is the norm.

Nice..this could come in handy for me as well...got any pics of your plating setup?
Title: Re: RD400 - Back from the Dead
Post by: JSJamboree on Jun 19, 2017, 10:03:18
Nice..this could come in handy for me as well...got any pics of your plating setup?

this, I tried once and it was a failure
Title: Re: RD400 - Back from the Dead
Post by: AimlessMoto on Jun 19, 2017, 10:46:27
Nice..this could come in handy for me as well...got any pics of your plating setup?

I will, once it's setup and ready to go.

A little bit of downer news today.

The machinist didn't have a bore-bar small enough to do a 2.5" cylinder...

I talked to him for about an hour about other steps to take, and how to do this... he said, because I'm removing less than .5 of a mm on once cylinder, and less than .2 of a mm on the other, that a hone-block with coarse stones will be fine.

The steps he gave me were to:

1- Take initial measurements of the bore.
2- Fit the piston (if possible) and use a feeler gage to get a starting point.
3- Mic the hone so that it's square top to bottom (80 grit stones).
4- Use lots of cutting oil, and don't exceed 600rpm on the tool.
5- Hone a small section of the bottom of the cylinder to gage how fast it will cut under medium pressure.
6- Hone the cylinder top to bottom, not allowing the stones to come out of either end.
7- Stop frequently, clean the bore, re-measure.
8- Once you're close to spec, swap out to finer grit stones (320), re-square the hone.
9- Medium pressure, full strokes for a few seconds.
10- Final pass needs to be slow speed, fast-pulls, dry, medium pressure to cut in the 45 degree hone.

Should be a fun time.
Title: Re: RD400 - Back from the Dead
Post by: clem on Jun 19, 2017, 18:27:46
Is this guy going to chamfer the ports for you too?

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Title: Re: RD400 - Back from the Dead
Post by: AimlessMoto on Jun 19, 2017, 23:18:26
Im going to be doing ALL of the work myself... bore, hone and port chamfering.
Title: Re: RD400 - Back from the Dead
Post by: AimlessMoto on Jun 28, 2017, 11:17:47
Have yet to bore the cylinders... just waiting on a day where I have nothing else going on so I'm not distracted.

Was able to get a TON of parts cleaned up-

Glass-Bead Blasted:
Headlight Housing
Wheels
Cases
Swingarm
foot pegs
passenger pegs
some of the really nasty parts of the frame (will be sanding the rest)
headlight mounts
triple trees
battery box
and a bunch of other doo-dads

Almost ready to start slinging paint on all the black stuff.

I was also able to separate the brake pistons from the cylinders... little compressed air and a rubber stopper sent the things hurtling across my garage... real fun.

Cleaning up the calipers getting them ready for paint, rebuild kits for the rear MC and both calipers are here, as well as a new crank o-ring, and some new stainless hardware.

The last thing to really "clean up" is some remaining hardware, but it's soaking in evaporust as we speak. That and cracking the halves on the engine.

Part of me really wants to get the bike back into a rolling-chassis before splitting the cases, just to clean up my shop a bit and not have so much clutter around. As it stands, my bike-bench is hardly usable because of all the hardware scattered about on it.
Title: Re: RD400 - Back from the Dead
Post by: AimlessMoto on Jun 30, 2017, 22:44:38
Made the last giant purchase today... tires, coils, paint, decals, and a bunch of odds and ends.

Also started bore-honing the cylinders. Got both started and matched to 65.20mm, time to take it slow and get them to spec. Only took about 15 minutes to take off .20mm!

Heres a few shots of the sandblasted parts as well.
Title: Re: RD400 - Back from the Dead
Post by: AimlessMoto on Jul 06, 2017, 13:03:10
Cylinders are finally done!

A .0020" feeler pinches, and a .0010" slides right in... took some measurements with the dial-bore gage and the cylinders are within .0005 of each other, and within about .0013-.0016 to the pistons. Ring gap is spot-on at .011" on the right and .013" on the left. Not too bad. The cylinders are also dead-round now.

Chamfered the ports with an angled file, and everything is smooth to the touch. Top of the piston at the head has .0020" of clearance.

I figure the rings are going to chew a little of the cylinder away during break-in.. at least smoothing out the hone a little, so tighter would be a little better.

Hopefully with a dino-oil break in and running synthetic for the rest of it's life I'll get another 10-15k out of this top end.

Here are some pics.
Title: Re: RD400 - Back from the Dead
Post by: AimlessMoto on Jul 12, 2017, 17:22:59
Been plugging away. Got all but the clutch-cover in paint... still have to strip and blast the clutch cover. Replaced all the seals, and will have to flush and check the oil pump. New lines were ordered in clear so I can see what's going on.

Split the cases, cleaned up the mating surface and all the old gas from the crank case. New seals in, transmission and shifter dogs look brand new! Not bad for 12k miles!

Got my new tires in as well as painted and polished the fins on the heads... next will be the cylinders. Got the rear MC pained and threw some new guts in it... almost looks new!
Title: Re: RD400 - Back from the Dead
Post by: e30 gangsta on Jul 14, 2017, 14:23:58
You going to rebuild/weld that crank back up?
Title: Re: RD400 - Back from the Dead
Post by: AimlessMoto on Jul 14, 2017, 20:17:13
You going to rebuild/weld that crank back up?

Outside bearings and seals only. Inside bearings are in great shape. Weld what?
Title: Re: RD400 - Back from the Dead
Post by: clem on Jul 14, 2017, 21:50:36
He's probably talking about the crank pins.

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Title: Re: RD400 - Back from the Dead
Post by: AimlessMoto on Jul 26, 2017, 12:49:51
Crank is fine. No play in inner bearings or lower rod end bearings... so it stays.

The oil pump on the other hand... sheesh. I had the bright idea to take it apart... stupid me. Lost one of the tiny detents on the manual pump bypass. I ordered some 2mm x 10mm rods from England a couple weeks ago... they should be in soon, going to cut them down and make a few extra 2mm x 3.5mm rounded detents just in case that happens again.

I also painted the frame... I am NEVER using PJ1 paints again. The nozzles clog constantly, and the finish is really poor on the gloss black. I am leaving it, as the worse parts won't be seen... but it's not worth $15 a can for the finish it provides. I'll stick to VHT Engine/Caliper/Rollbar and Chassis paints from now on.

Parts are coming together nicely...
Title: Re: RD400 - Back from the Dead
Post by: Turnturtle on Jul 26, 2017, 13:24:01
Those oil pump pins look just like lock pins. I have some in 2mm x 4mm in brass. A locksmith would have the size you need.
Title: Re: RD400 - Back from the Dead
Post by: jpmobius on Jul 26, 2017, 13:51:46
Right, those little pins come out like bullets if you don't know they are there.  Trick is to do that part of the disassembly inside a clear plastic bag.  Be sure to inspect the check valves.  They are under the brass nipples pressed into the pump case that feed the two carb oil supply lines.  Probably they are fine, but check with WD40 or something similar while you have the pump apart.  Don't use compressed air.  If they don't seem right, pull out the brass nipples.  Usually they are fairly easy to twist a bit while pulling on them.  There is a spring and check ball inside so be careful.  Rusty spring is the only problem I have seen which is rare as the thing is always full of oil.
Title: Re: RD400 - Back from the Dead
Post by: AimlessMoto on Jul 26, 2017, 16:59:04
Right, those little pins come out like bullets if you don't know they are there.  Trick is to do that part of the disassembly inside a clear plastic bag.  Be sure to inspect the check valves.  They are under the brass nipples pressed into the pump case that feed the two carb oil supply lines.  Probably they are fine, but check with WD40 or something similar while you have the pump apart.  Don't use compressed air.  If they don't seem right, pull out the brass nipples.  Usually they are fairly easy to twist a bit while pulling on them.  There is a spring and check ball inside so be careful.  Rusty spring is the only problem I have seen which is rare as the thing is always full of oil.

Good call. The first thing I did was drain, clean with parts cleaner, then threw my new clear lines on and ran the pump slowly on a drill from the plastic gear (a small flat-head fit in the hole by the cotter pin). I manually held the pump at wide-open and spun the drill... a bunch of old oil and gunk came out. I then threw a little 0w-20 I had laying around in and it pumped it out nice and clean with no air bubbles. Drained, cleaned again, and now it's in pieces waiting the pin.

I never thought of using a lock pin... the original are steel, so I want to keep them steel if possible.
Title: Re: RD400 - Back from the Dead
Post by: AimlessMoto on Jul 27, 2017, 18:54:19
Cut down a 2mm dowel to replace the one I lost. Back to putting this fiddly thing together. Just waiting on the gasket and oil seals to come in.
Title: Re: RD400 - Back from the Dead
Post by: AimlessMoto on Jul 31, 2017, 14:05:54
BIG progress this weekend. Closed up the cases, new sprocket, all new seals, re-painted the cases to a more stock-color... semi-gloss black instead of satin.

I was also able to get the clutch side closed up, and put the piston and jugs back on, but haven't taken pictures yet.

Everything going together smoothly so far.

Also re-did the forward controls for the handlebars.

I checked the run-out on the pump at "idle" with no cable on the pump, and it's got about .007" of throw... manual says it needs .008-.012, so I'm probably going to order a new shim.
Title: Re: RD400 - Back from the Dead
Post by: AimlessMoto on Aug 01, 2017, 08:25:59
And we are back together. Starting to look good. Much better than when I picked it up. I think it'll get tossed back into the frame before going any further.
Title: Re: RD400 - Back from the Dead
Post by: advCo on Aug 01, 2017, 13:45:30
Much better. Nice work.
Title: Re: RD400 - Back from the Dead
Post by: CrabsAndCylinders on Aug 01, 2017, 15:29:12
Well done!
Title: Re: RD400 - Back from the Dead
Post by: AimlessMoto on Aug 02, 2017, 11:44:20
Thanks guys!
Title: Re: RD400 - Back from the Dead
Post by: AimlessMoto on Aug 03, 2017, 11:21:05
In the frame! Now I just have to finish painting the engine mounts and peg mounts to finalize.

I was able to get everything plumbed as far as Tach cable, throttle/pump cable, alternator harness and points (with new points and condenser), all the breather tubes for the carbs, transmission vent, etc. I'm waiting on getting the mounts in before I finalize the airbox boots and torqueing the heads to 15lbs. Then I will do a squish test. I'll have to wait to clean up the harness and install the battery before I can time the thing. I don't have a dial gauge that will rest in the plug hole. I could, however try to make something work. We'll see.
Title: Re: RD400 - Back from the Dead
Post by: Uglyrabbit on Aug 04, 2017, 06:48:32
Keep up the good work, it looks great!


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Title: Re: RD400 - Back from the Dead
Post by: Ryan Stecken on Aug 04, 2017, 08:46:12
make sure to bleed these oil lines from the oil pump before yu run it :-)
Title: Re: RD400 - Back from the Dead
Post by: AimlessMoto on Aug 04, 2017, 14:31:07
make sure to bleed these oil lines from the oil pump before yu run it :-)

Yup! Gotta shim the pump and install the oil tank. Hopefully this weekend!
Title: Re: RD400 - Back from the Dead
Post by: AimlessMoto on Aug 14, 2017, 10:41:35
Lots of progress this weekend. Decided to do something a little different with the wheels and do a hybrid XS650/Daytona sort of look... polished the ribs, taped them, and spray-bombed them gloss black. I absolutely love how they look... also re-finished the disc hubs the same way (like stock).

I also got my shims in for the pump and it's now gapped to .010 at full swing at idle. Once that was sorted I threw the pegs and exhaust on, as well as both of the kickstands and springs... now it's finally held up under it's own two wheels for the first time in a few months!

Lastly, I got the brakes rebuilt, but the front one leaked like crazy out of the pistons. There was simply too much corrosion damage to keep a tight seal, so a brand new front caliper is on order. The rear one is holding up well so far, looses a little pressure over night, so there's probably still an air bubble in the master cylinder or in the top of the line. Going to vacuum bleed it after the rear wheel is fully installed.
Title: Re: RD400 - Back from the Dead
Post by: AimlessMoto on Aug 21, 2017, 15:52:49
New front MC and Caliper with steel braided line installed. Not getting the feel I want, going to take a while to bleed I think. Might try to reverse-bleed, or take the pads out and make sure there's no air behind the pistons.

Wiring harness back in. Made a new dedicated ground out of some 10ga wire from the engine, to the frame, to the negative on the battery.

Got everything to work, all the bulbs are good... only problem is the flasher isn't really doing anything. It'll flash left, sometimes, but won't flash right, just stay on. Took the flasher unit apart, seems to be OK... might just be to low voltage with the bike not running.

I bypassed the resistor on the new coils (as suggested by the manufacturer) and I'm getting spark... all-be-it a small-ish purple one. Again, may be due to the point gap... condensors and points are new, so should just be in the adjustment. Waiting on a 2-stroke adapter for my dial gauge to come in so I can properly time it. Going to shoot for 1.8mm BTDC as everyone seems to have good luck there.

Tank is currently soaking in vinegar, already looks amazing... just going to drain it and coat it with some 2 stroke oil on the inside until I'm ready to install it. New petcock will be fitted as well.

Getting there! Oil in the trans, bled the oil lines for the injection system... it's been sitting 3 days and no bubbles have occurred, so hopefully that means the ball-valves are good and there are no air-leaks. Battery is fully charged. Carbs are synced, pump is adjusted.

Only electrical problem I have is that the kill-switch is dead... so I just taped a jumper into the connection. I'll deal with this down the road.

Last on the list:
-Set the tire pressure.
-Set the points and timing.
-Get the dent out of the speedo housing and refurb the gauge bracket and housings. 
-Nut-and-bolt check the entire bike.
-Try to start it.
-Adjust idle, carb balance, air screws if it starts and runs.
-Check for gremlins.
-Break it in.
Title: Re: RD400 - Back from the Dead
Post by: goldy on Aug 21, 2017, 17:32:56
That's looking really nice!Some top quality work there. :D
Title: Re: RD400 - Back from the Dead
Post by: jpmobius on Aug 21, 2017, 22:33:05
Try bleeding the brake fluid at the banjo bolt at the MC.  It is messy, so get lots of protection.  If the action is not confidence inspiring, there is air.  Possibly you will have to continue bleeding air out of the caliper, but my money is on air at the MC itself.  My process is barbaric, but quick, easy and works 100% of the time so far (in hundreds of applications at least).  For this bike, fill with brake fluid and after stuffing crazy amounts of paper towels around the caliper crack the bleed screw.  Hold your finger over the outlet of the bleed screw and pump the lever.  Use your finger like a one way valve on the bleeder.  After a few pumps, and there is no need to coordinate the person pumping with the person bleeding - just give it a few full slow pumps and don't worry about sucking air back on the down stroke, your finger will keep that from happening.  Close the bleeder and bleed the banjo bolt at the MC.  All should be fine if the MC was maintained with fluid.  I use basically the same method on everything with hydraulic brakes.  Cars take about 15 minutes with all new brakes, MC and dry lines.  Messy, but not really much more than with drain lines, collection bottles, pumps etc.  And the only thing to clean is the spill and vehicle which is tiny if you are careful.  I have NEVER needed a vacuum pump or had to "back fill" any brake system on any kind of vehicle - though I have had some stubborn cooling systems !

Lovely job your doing here - keep it coming!
Title: Re: RD400 - Back from the Dead
Post by: AimlessMoto on Aug 22, 2017, 11:54:23
Try bleeding the brake fluid at the banjo bolt at the MC.  It is messy, so get lots of protection.  If the action is not confidence inspiring, there is air.  Possibly you will have to continue bleeding air out of the caliper, but my money is on air at the MC itself.  My process is barbaric, but quick, easy and works 100% of the time so far (in hundreds of applications at least).  For this bike, fill with brake fluid and after stuffing crazy amounts of paper towels around the caliper crack the bleed screw.  Hold your finger over the outlet of the bleed screw and pump the lever.  Use your finger like a one way valve on the bleeder.  After a few pumps, and there is no need to coordinate the person pumping with the person bleeding - just give it a few full slow pumps and don't worry about sucking air back on the down stroke, your finger will keep that from happening.  Close the bleeder and bleed the banjo bolt at the MC.  All should be fine if the MC was maintained with fluid.  I use basically the same method on everything with hydraulic brakes.  Cars take about 15 minutes with all new brakes, MC and dry lines.  Messy, but not really much more than with drain lines, collection bottles, pumps etc.  And the only thing to clean is the spill and vehicle which is tiny if you are careful.  I have NEVER needed a vacuum pump or had to "back fill" any brake system on any kind of vehicle - though I have had some stubborn cooling systems !

Lovely job your doing here - keep it coming!

Thanks! I tried your suggestion last night. I did take the caliper off first and ensure both pistons moved when hitting the brakes... then I back-flushed out the bleeder instead of up the line to the MC. I then filled the MC and pumped it a bunch to get as my of the little air bubbles out as possible... THEN I started your method. The "finger over the bleeder" doesn't make much sense. I tried, and tried, but couldn't get any pressure built up it would simply push past the threads in the bleeder or my finger.

I put a hose back on the bleeder and bled as normal... 10 pumps, crack the bleeder, watch for bubbles. Not many if any came out.

I then did the MC bleeding as you suggested. 10-15 full pumps, crack the banjo, get sprayed, close the banjo, repeat.

This did firm up the lever a bit, but I can still pull it back to the bars, all be it slightly stiffer than before. I'm wondering if the MC has more throw than the bars allow... I may try to take the MC off and mount it to the center of an old handlebar I have to try and get more throw out of the lever. It may be what's preventing all the air coming out of the MC. I've heard a lot of people fix this problem by drilling and tapping the lever to install an adjuster bolt in the tab that touches the plunger in the MC...

Title: Re: RD400 - Back from the Dead
Post by: kiki.o on Aug 23, 2017, 16:49:25

Maybe I have missed the info, but, what brand of color did you use for engine painting? Great work so far!
Title: Re: RD400 - Back from the Dead
Post by: AimlessMoto on Aug 24, 2017, 08:25:37
I originally used satin black PJ1 epoxy, but it came out too dull, so I went over it again with DupliColor Engine paint in "Ford Gloss Black".

The wiring is 100%! I was able to fix the dent in my speedo housing with some strategic punch work and a skim coat of bondo. Not terrible, but perfect from about 3 feet away (which is all you need).

Headlight back on, trying to over-night bleed the brakes again. I may have a MC issue at this point, luckily I have a spare.

Just waiting on the adapter for my dial gauge to come in so I can time the thing and set the points!

Title: Re: RD400 - Back from the Dead
Post by: SONIC. on Aug 24, 2017, 10:27:47
Looking good!
Makes me regret selling my RD400
Title: Re: RD400 - Back from the Dead
Post by: AimlessMoto on Aug 25, 2017, 08:23:26
Last night I was able to pull the baffles, check for carbon (hardly anything in there), set the points gap to .014", set the timing to .070" (1.8mm) BTDC, put the new petcock on the tank (had to wait to source some fiber washers, found them at the hardware store for .20c!), and threw some fresh gas in it....

It started 3rd kick! Needs some adjustments, but it runs!
Title: Re: RD400 - Back from the Dead
Post by: Maritime on Aug 25, 2017, 08:51:57
Nice work, back from the dead for sure.
Title: Re: RD400 - Back from the Dead
Post by: stroker crazy on Aug 25, 2017, 18:49:42
It started 3rd kick!

Good work!

Crazy
Title: Re: RD400 - Back from the Dead
Post by: goldy on Aug 26, 2017, 07:25:11
Very nice work, you should be proud of the results!

Now for some riding and tuning!  :D
 
Title: Re: RD400 - Back from the Dead
Post by: LaVolpe on Aug 27, 2017, 13:58:14
Absolutely inspiring, it's nice to see these old bikes being brought back to their former glory. Makes me want to do a full rest on my GT250.
Title: Re: RD400 - Back from the Dead
Post by: AimlessMoto on Aug 29, 2017, 10:55:16
Thanks for the responses!

Currently battling 3 gremlins.

1- Rebuilding the Tach.. all the dashpot oil turned to molasses and it was non responsive. Its torn down waiting fluid. (You can see in the picture the clear lid removed form the pot.) 

2- the LH carb keeps overflowing. I checked float height and its spot on, I think its hitting the inside of the bowl. (I just had them off to chase a bad idle issue... check those emulsion tubes!)

3- Slight top end rattle on the RH cylinder. I think the rings are binding causing the piston to rock on the rings... tore it down and there was minor scoring. Going to double check the bore later this week. Hopefully another quick fix.
Title: Re: RD400 - Back from the Dead
Post by: jpmobius on Aug 29, 2017, 13:12:00
A common reason for the bowls overflowing is the float mechanism hanging up.  Make sure the floats slide smoothly on their pins obviously, but closely examine the brass arm.  If there are ANY wear marks on either the arms where the float pins push on them or on the tab that pushes on the needle, smooth them out perfectly flat with a fine file or sandpaper block and then polish them smooth with at least #600 sandpaper.  Both areas tend to wear only where the fuel level is maintained, and the tiniest hump or notch will keep adequate pressure from the needle.  Also a good idea to polish the needle and seat with a Q-tip and rubbing compound as well as the bore for the needle.  Always use OEM needle and seat assemblies as aftermarket parts are often slightly different in assembled length which screws up the geometry for proper fuel level, though unless you see actual wear or damage to the ones you have you won't need to replace them to correct the problem.  Often it is perceived that replacing the assembly cures the overflow issue, when actually the tiny physical difference in the parts moves the set point slightly enough to no longer  hang the mechanism at previous wear point.
Title: Re: RD400 - Back from the Dead
Post by: clem on Aug 29, 2017, 21:54:14
On an unresponsive or erratic tach or speedometer you can soak a cotton ball in kerosene and place it in one of the back light holes. Place the gauge upright for a few days and it will oil it up without disassembly.

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Title: Re: RD400 - Back from the Dead
Post by: CrabsAndCylinders on Aug 30, 2017, 01:46:56
On an unresponsive or erratic tach or speedometer you can soak a cotton ball in kerosene and place it in one of the back light holes. Place the gauge upright for a few days and it will oil it up without disassembly.

Sent from my SAMSUNG-SM-G930A using DO THE TON mobile app (http://r.tapatalk.com/byo?rid=89466)

Wow, that's good tip!
Title: Re: RD400 - Back from the Dead
Post by: AimlessMoto on Aug 30, 2017, 15:08:20
A common reason for the bowls overflowing is the float mechanism hanging up.  Make sure the floats slide smoothly on their pins obviously, but closely examine the brass arm.  If there are ANY wear marks on either the arms where the float pins push on them or on the tab that pushes on the needle, smooth them out perfectly flat with a fine file or sandpaper block and then polish them smooth with at least #600 sandpaper.  Both areas tend to wear only where the fuel level is maintained, and the tiniest hump or notch will keep adequate pressure from the needle.  Also a good idea to polish the needle and seat with a Q-tip and rubbing compound as well as the bore for the needle.  Always use OEM needle and seat assemblies as aftermarket parts are often slightly different in assembled length which screws up the geometry for proper fuel level, though unless you see actual wear or damage to the ones you have you won't need to replace them to correct the problem.  Often it is perceived that replacing the assembly cures the overflow issue, when actually the tiny physical difference in the parts moves the set point slightly enough to no longer  hang the mechanism at previous wear point.

The second time I had it apart, I thought it was hanging up on the non OEM gasket I had installed. I could place the bowl on, shake the carb up and down, and couldn't hear the float jumping.

The needle and seat are stock, with 0 wear on them. They seal at the slightest touch of the float when the carb is on it's side.

I think the problem is that the floats themselves are hitting the sides of the bowl. The float hinge pin is smooth as silk, and the little spring plunger is working in the needle correctly.
Title: Re: RD400 - Back from the Dead
Post by: AimlessMoto on Aug 30, 2017, 15:12:00
On an unresponsive or erratic tach or speedometer you can soak a cotton ball in kerosene and place it in one of the back light holes. Place the gauge upright for a few days and it will oil it up without disassembly.

Sent from my SAMSUNG-SM-G930A using DO THE TON mobile app (http://r.tapatalk.com/byo?rid=89466)

Really?! This stuff was STUCK on. I needed to hit it with brake-cleaner to remove it, and the dash-pot was completely empty. It basically puked itself into and around the friction (centripetal) drive. It was dead from 0-3000 RPM, then jumped from 3000 to redline (on a drill) and then hung up around 4000 when letting it drop to 0. The bike was stored at a 45 degree angle for 10 years up against a tree, outside, with a tarp over it with the bars turned. Basically the worst way to possibly store a tach... lol.

I just filled it up with silicone 50000cts oil (RC Car Differential Oil, basically) and it works perfectly! I just stuck it back together last night and re-installed. It's super responsive, drops back to 0 smoothly, and holds steady at all RPM. I was testing it with a cordless drill, as currently I don't want to run the bike until I get the top end sorted.
Title: Re: RD400 - Back from the Dead
Post by: teazer on Aug 30, 2017, 16:20:09
I missed something here.  Were the carbs rebuilt and if so why is there so much corrosion on the needle jet?

How do the floats touch the bowl and stick?  There's not a huge amount of clearance in there but they can't touch unless they are quite badly bent.
Title: Re: RD400 - Back from the Dead
Post by: jpmobius on Aug 30, 2017, 19:02:45
How do the floats touch the bowl and stick?  There's not a huge amount of clearance in there but they can't touch unless they are quite badly bent.

Right.  It should be super easy to eliminate this as problem - just put the floats on their pins and set the gasket on the bowl and see if they can touch.  I've never seen this as a problem, but it is totally possible especially if the gasket is old, used, and dried out.  I just looked at one that has been parked on my desk for forever and the gasket has shrunk a bit and curved inward toward one of the floats.  It isn't hanging the float, but I can see it doing so potentially.  Easy to trim a bit off the inside and eliminate it as a problem though.
Title: Re: RD400 - Back from the Dead
Post by: AimlessMoto on Oct 03, 2017, 14:47:07
Quick little update.

Carbs are back to 100%. I was getting a back knock on the right cylinder, took it all apart and it turns out I was out of round. I was hoping the honing would've fixed it, but it seemed to have made things worse.

I took the cylinders off and mailed them out to a machinist friend. He's got them squared up, bored out, and honed, just waiting on getting them back.

The floats WERE touching the sides of the bowls... a quick tweak and re-check before re-assembly and they're 100% now. No leaks.
Title: Re: RD400 - Back from the Dead
Post by: AimlessMoto on Oct 09, 2017, 14:32:14
Bit more digging, found my air/fuel screw O-rings were completely shot... got some new ones on the way.

Also got my cylinders back from the machine shop... they look amazing. Pics to come.
Title: Re: RD400 - Back from the Dead
Post by: AimlessMoto on Oct 16, 2017, 09:44:36
Top-end came back from Supertune1. Amazing quality of work. Jugs and pistons installed no problem. Chuck had mentioned he noticed a lot of grit in the cylinders, I thought it was from the honing blocks I used, but upon closer inspection there was SAND in my air box...

I completely disassembled the air box, washed it out with dish soap and simple green, and hit it with a scrub brush. No more sand. Really concerning... Hopefully it was just something I missed during the first go-around.

I was able to get the engine back together, checked and re-checked the float height on the carbs, re-synced and re-cleaned... I'm just waiting on new air-screw o-rigs... should've been here Saturday, but looks like Monday/Tuesday now. They're literally the only thing I need to kick it over and start break-in.

Here's some pics of the progress.

Title: Re: RD400 - Back from the Dead
Post by: AimlessMoto on Oct 16, 2017, 09:48:06
Glamour shots with the new mirrors...
Title: Re: RD400 - Back from the Dead
Post by: AimlessMoto on Oct 16, 2017, 09:57:47
I also re-set the timing to 1.85mm btdc, and re-bled the oil lines.
Title: Re: RD400 - Back from the Dead
Post by: SONIC. on Oct 16, 2017, 10:00:41
soooooo....
how does it ride?
Title: Re: RD400 - Back from the Dead
Post by: AimlessMoto on Oct 16, 2017, 11:12:41
Waiting for the O-rings for the idle air screws... then I'll fire it up.
Title: Re: RD400 - Back from the Dead
Post by: goldy on Oct 16, 2017, 14:58:33
Glad you have it back together. Sand eh?...bad news for any engine, but especially a two stroke...I hope it didn't get into the main or con rod bearings.  :o
Title: Re: RD400 - Back from the Dead
Post by: AimlessMoto on Oct 16, 2017, 15:10:24
I washed out the crank case about 5 times with mineral spirits, then a little ATF, then more mineral spirits... each time the spirits came out more and more clear. I would spin the crank with a drill on the stator side with cardboard taped around the cylinder studs and rubber bands through the wrist pin holes to suspend them in the center of the 'bore'.

There is zero gritty feeling on the crank. I think if anything made it into the crank case of the 15-20 mintues this bike ran it either blew straight out the exhaust, or was in the base of the crank case.

I went through after with a can of brake clean and the air compressor. Then quickly hit everything with some dino 2-stroke oil.
Title: Re: RD400 - Back from the Dead
Post by: clem on Oct 16, 2017, 21:33:11
Chuck is one of d'best around.

Sent from my SAMSUNG-SM-G930A using DO THE TON mobile app (http://r.tapatalk.com/byo?rid=89466)

Title: Re: RD400 - Back from the Dead
Post by: AimlessMoto on Oct 20, 2017, 22:54:57
Screws came with the right o-rings... she fired on the 1st kick and smoked me out. SUCCESS!


She runs like a sewing machine! Warmed it up, rode it for 5 mins, let it cool down.

Going to check the head bolts and start the break in process. Shes PEPPY!
Title: Re: RD400 - Back from the Dead
Post by: 3DogNate on Oct 20, 2017, 23:20:48
Looking great... nothing like the smell of 2 stroke oil.
Title: Re: RD400 - Back from the Dead
Post by: stroker crazy on Oct 21, 2017, 01:03:34
Shes PEPPY!

Easy to believe!

Crazy
Title: Re: RD400 - Back from the Dead
Post by: goldy on Oct 21, 2017, 08:09:15
I've been smoked out a few times myself...fun ain't it! :)
Title: Re: RD400 - Back from the Dead
Post by: AimlessMoto on Oct 25, 2017, 09:39:35
Ran into another odd-ball issue.

It fired up and ran great about 4 times in a row... then on the 5th time (this is after significant cool-down between start-ups). It would backfire. I had the tank on "RES".

I went chasing electrical thinking it was the points, maybe a bad switch, but no... everything was working perfect. Big, fat purple spark on both plugs in both boots... so not the coils.

I decided to pull the fuel hoses and check the petcock for flow.

On RES, I had barely a trickle out of the outlet going to the LH carb... the RH carb was fine.
On ON, I had full flow.

I looked in the tank and the fuel level was about an inch below the "ON" pickup. WTF?

I took the bowl off the petcock and a bunch of sediment was in there. Which is odd, because I soaked the tank in vinegar for 3 days in all different positions and rinsed it out VERY well with distilled water and baking soda, then again with some 2-stroke gas.

There may be some cancer inside the tank I can't see that's causing this.

ANYHOO... cleaned the petcock, added fresh gas, then it fired right up and I took it for a ride... all was normal.

Looks like some Kreem is in my future, but for the time being a couple of 90-Micron screen filters and an extra tank flush will have to do.

This was the result of 2 cups of fuel run through the petcock. I poured most of the fuel off... but there's a good amount of jet-clogging junk here.

Title: Re: RD400 - Back from the Dead
Post by: stroker crazy on Oct 25, 2017, 09:50:34
Looks like some Kreem is in my future

Looks nasty!

(Caswell works well)

Crazy
Title: Re: RD400 - Back from the Dead
Post by: jpmobius on Oct 25, 2017, 12:04:56
Remove your petcock and make sure the screen over the reserve inlet is ok.  Then make sure the screen that covers the sediment bowl is ok.  You shouldn't need anything but these two screens.  Take off the sediment bowl regularly and check for contaminants.  After you run through a few tankfuls things should be fine.  Don't use any sealer on your tank unless it leaks!!!  Especially kreme, which is the worst thing you can do to a tank.
Title: Re: RD400 - Back from the Dead
Post by: goldy on Oct 26, 2017, 08:22:52
I'll second that..DON"T use Kreem! There is always some corrosion sediment/ flaking after you clean a tank, it will flush itself out over time. If you MUST line it, use something like Caswell or POR 15.
Title: Re: RD400 - Back from the Dead
Post by: AimlessMoto on Oct 27, 2017, 14:25:03
After a flush the sediment is gone... i wont Kreem... but i did find a pinhole leak by the air box on the left hand side on the bottom of the tank... i think it can be welded.  ::)

Found my screen in the petcock was backwards so on was res and vicea-verse...

Lastly, i was still getting bad backfires so I threw in new points and plugs.

She runs better than ever now! Timing set at 1.95mm and both cylinders read 205 degrees after blasting around the neighborhood a bit.

NOW i have enough confidence to break this thing in out on the road...
Title: Re: RD400 - Back from the Dead
Post by: goldy on Oct 27, 2017, 19:49:37
I suggest you try solder rather than weld on that pinhole...a bit of acid flux and a good hot soldering iron. No flames, no boom! :D
Title: Re: RD400 - Back from the Dead
Post by: AimlessMoto on Oct 31, 2017, 10:27:18
I agree. This winter I'm going to chem strip the tank, glass blast any rust pits, and then do a pressure test to see where she's leaking... I'll rinse with alcohol and air-purge before hitting it with the iron.