Thanks boingk. I understand what the chambers do, but not well enough to design a pair or anything. Probably some applications out there that calculate...but having a set welded would cost a fortune. Here's a look at the dg http://home.comcast.net/~todwatts/motorcycle_7_mods.htm#exhausts as you can see it lacks a stinger, maybe just cutting off the last section and welding a stinger on would help. I'm not sure exactly how you fit a silencer then without the pipes being really long?? I am definitely willing to find a used pair and cut/weld them up. Actually, Dennis Kirk sells them for $230 shipped! Weird, DG makes a much nicer set for the RZ for around the same price.
Yamaha 2 stroke
- Thread starter perattzi
- Start date
boingk
Standard gearhead.
To be honest, I've never seen those type of silencers around here. I'm a lot more familiar with the real 'stinger' setup as per below.
The small diameter tube at the end is critical for control of exhaust pulses so they don't simply rush back out the chamber and leave it with no internal pressure. The length isn't as critical as the diameter in this equation, so you can make them long enough to properly mount aftermarket silencers. The silencer attachment is usually nothing more than a flat donut of steel with mounting holes for the silencer, and you can either weld this straight to the stinger or buy it so its removable with a collar and grub-screw.
This will look class if you do it right, and it shouldn't be too hard - check out the picture above and see how they've done it. Any questions just ask me as I've done all this on my late Aprilia RS125 (and my brothers).
Cheers - boingk
The small diameter tube at the end is critical for control of exhaust pulses so they don't simply rush back out the chamber and leave it with no internal pressure. The length isn't as critical as the diameter in this equation, so you can make them long enough to properly mount aftermarket silencers. The silencer attachment is usually nothing more than a flat donut of steel with mounting holes for the silencer, and you can either weld this straight to the stinger or buy it so its removable with a collar and grub-screw.
This will look class if you do it right, and it shouldn't be too hard - check out the picture above and see how they've done it. Any questions just ask me as I've done all this on my late Aprilia RS125 (and my brothers).
Cheers - boingk
Hey, I found this after some searching... http://www.2strokeworld.com/forum/index.php?topic=2032.0 just what I needed...looks like what you explained is just what this guy did (did you mean to attach a pic?). Doesn't look too hard. And for the length of the stinger, most things I read say to make it long and just cut it down to what works best. Anyway, I ordered a set of DG chambers tonite...230 shipped brand new is a damn good deal, I'll probably just throw them on and, sort out the jetting and see what I think about them. And for the money, i won't feel bad about cutting them up a few months down the road if that's the case.
On another note, some places sell reed block spacers, that they claim can alter the powerband depending on where you mount them, before or after the reed, seems like another semi-cheap way to experiment. Only bugger is all the rejetting and clip moving with these things. BTW those RS125's are sweet! Too bad we can't buy those for road use...I don't get it, 2 strokes have come so far since when they were banned. They make a big fuss over some little smokers...which are peanuts compared to most pollutants. Poor city planning is way worse...everybody gets in their car alone and drives everywhere to do any little thing over here...so silly.
On another note, some places sell reed block spacers, that they claim can alter the powerband depending on where you mount them, before or after the reed, seems like another semi-cheap way to experiment. Only bugger is all the rejetting and clip moving with these things. BTW those RS125's are sweet! Too bad we can't buy those for road use...I don't get it, 2 strokes have come so far since when they were banned. They make a big fuss over some little smokers...which are peanuts compared to most pollutants. Poor city planning is way worse...everybody gets in their car alone and drives everywhere to do any little thing over here...so silly.
boingk
Standard gearhead.
Yeah man, thats exactly what I mean! The pic I posted was just of a bike which looked like his 'finished' photo from the rear 3/4 view to show off the pipe and silencer. Still can't believe you're getting the chambers for 230 a set!!! Man oh man...
Anyway, even if you take it to a welder and explain what you want done it'll probably be either gratis or something paltry like $10~20. At least, thats what the guys around here are like.
On the RS, I regret selling it but I don't regret what I bought afterwards. Mine was the last eyar they didn't have a catalyser in the expansion pipe - you can tell which ones do if they're off the bike since they have rivets in them in the dwell area. They say we might be going back to strokers - citroen and KTM are going hammer and tongs at them! Citroen with pneumatic valves so you can put your foot down and its a stroker for max power, of cruise on 4-stroke mode with cylinder shut-down. KTM is developing direct-injection strokers...can't wait!
Cheers - boingk
Anyway, even if you take it to a welder and explain what you want done it'll probably be either gratis or something paltry like $10~20. At least, thats what the guys around here are like.
On the RS, I regret selling it but I don't regret what I bought afterwards. Mine was the last eyar they didn't have a catalyser in the expansion pipe - you can tell which ones do if they're off the bike since they have rivets in them in the dwell area. They say we might be going back to strokers - citroen and KTM are going hammer and tongs at them! Citroen with pneumatic valves so you can put your foot down and its a stroker for max power, of cruise on 4-stroke mode with cylinder shut-down. KTM is developing direct-injection strokers...can't wait!
Cheers - boingk
You sold the other bike? That was one of my favorites on here.
For the RD, I recommend tip-toeing into this. If you got the DGs, stop there and get the jetting and timing sorted. Having gone through a lengthy tuning process, I would have started with an electronic iggy, but that's me. Since you have the pipes, start there. Once sorted, move on to a single K&N and tune to suit. Then move on to balance tube and new reeds. Don't mess around with new reed cages or reed blocks now.
The point is not to try everything all at once. I run the DGs as-is and don't have any problems. Yeah, it's not ideal, but it's hard enough to keep the front wheel down on my RD. Something to think about...
--Chris
For the RD, I recommend tip-toeing into this. If you got the DGs, stop there and get the jetting and timing sorted. Having gone through a lengthy tuning process, I would have started with an electronic iggy, but that's me. Since you have the pipes, start there. Once sorted, move on to a single K&N and tune to suit. Then move on to balance tube and new reeds. Don't mess around with new reed cages or reed blocks now.
The point is not to try everything all at once. I run the DGs as-is and don't have any problems. Yeah, it's not ideal, but it's hard enough to keep the front wheel down on my RD. Something to think about...
--Chris
Chris...yea I sold most of the KZ...I too loved the idea and had a vision for it...but Christ was it getting expensive. And after riding my RD for awhile, I knew where I wanted to put my resources. With the 650, the entire engine needed redone...just main bearings alone cost a fortune...easily over 2 grand to do it right. For the cost of KZ pistons and bore alone, I can do the RD top end and rebuild the crank.
Plus it was just taking too damn long...so the parts have gone to good places. Oh well, it was fun.
I'm with you on not trying to do everything at once, and I'm not planning to hack up the DG's right off the bat or anything. I thought about Spec II's but that would be double the cost of DGs. It's just nice to know that they can be modded fairly easily, although the details are still up in the air. I need to order handful of jets.
Did you switch to a y-boot intake setup? Or try the mod mimic the R5 carbs? Basically for now my plan is to get the pipes, k&n filter, electronic iggy, and a seat, then get on the road. Which ig did you go with? I hear the modified dyna works well without the $500 price tag.
I would like to ride a 400 sometime, they are supposed to be quite a bit different...with the longer stroke. Not as much of a handful on the street with a wider powerband and less vibration (the 350 motor is not rubber-mounted).
Plus it was just taking too damn long...so the parts have gone to good places. Oh well, it was fun.
I'm with you on not trying to do everything at once, and I'm not planning to hack up the DG's right off the bat or anything. I thought about Spec II's but that would be double the cost of DGs. It's just nice to know that they can be modded fairly easily, although the details are still up in the air. I need to order handful of jets.
Did you switch to a y-boot intake setup? Or try the mod mimic the R5 carbs? Basically for now my plan is to get the pipes, k&n filter, electronic iggy, and a seat, then get on the road. Which ig did you go with? I hear the modified dyna works well without the $500 price tag.
I would like to ride a 400 sometime, they are supposed to be quite a bit different...with the longer stroke. Not as much of a handful on the street with a wider powerband and less vibration (the 350 motor is not rubber-mounted).
Toomey's are the schnizit for these bikes if you can find them. The DG's are ok, and will wake it up, but not like a set of Toomey's. I have an exhaust calculator if you want it, but there are a few on the web. Just be forewarned that pipe tuning is a science and a pain, but nothing is like getting on the pipe on a properly set up stroker.
I think that 400 pipes will bolt to a 350, but I am not sure. I only ever played with rd400's. Look into a boost bottle as well. you can make your own, or get one from a banshee/400. A set of power jet's will work well also. You can get carbs pre drilled for them, or add in. a set of 32mm with power jets, some boysen reeds, a boost bottle and some pipes and you will need to hold on for dear life.
If your gonna keep the pump, you may want to go a little pre-mix just for safety after you mod the crap out of it... damhik
I think that 400 pipes will bolt to a 350, but I am not sure. I only ever played with rd400's. Look into a boost bottle as well. you can make your own, or get one from a banshee/400. A set of power jet's will work well also. You can get carbs pre drilled for them, or add in. a set of 32mm with power jets, some boysen reeds, a boost bottle and some pipes and you will need to hold on for dear life.
If your gonna keep the pump, you may want to go a little pre-mix just for safety after you mod the crap out of it... damhik
Ok, so I have taken to stripping all the old black paint off the wheels and whatnot...just don't really like the way it looks. I had a sweet Akront shouldered rim that would fit the rear perfect, but I can't find the damn thing. Alloy rims would be so sweet. But then the spoke holes may line up with my drum correctly anyway.
I'm even thinking of painting the bike a different color...I know the orange is special to the 75...but it's a respray anyhow. Will definitely sleep on that one though. Mocked my pipes up after much frustration...the right one still doesn't quite fit right. Having to bend and tweak is not what I like to do when forking cash for brand new stuff. OH well...
I'm going to start making a plug for a seat mold this weekend but can't decide what style I want!?!?!? I think I want something boxy i and racy instead of a hump, maybe even trackerish. I'm probably going to pick a seat shape that already exists and kinda tweak it. Here's a few i like...
I like this one but would make it smaller scale.
Kinda all over the place...leaning towards the first one
I'm even thinking of painting the bike a different color...I know the orange is special to the 75...but it's a respray anyhow. Will definitely sleep on that one though. Mocked my pipes up after much frustration...the right one still doesn't quite fit right. Having to bend and tweak is not what I like to do when forking cash for brand new stuff. OH well...
I'm going to start making a plug for a seat mold this weekend but can't decide what style I want!?!?!? I think I want something boxy i and racy instead of a hump, maybe even trackerish. I'm probably going to pick a seat shape that already exists and kinda tweak it. Here's a few i like...
I like this one but would make it smaller scale.
Kinda all over the place...leaning towards the first one
cierrecart
Been Around the Block
First one looks sweet. I think I'm going with a full upholstered seat from HVC.
Are you getting the one with the orange fabric? That is pretty sweet! Did you check out the ones on ebay? They look pretty awesome too...i emailed the seller to see if he had a picture of the seat actually mounted on a RD, but no response. So many seats look cool, but with the RD350 being so small alot of them look out of proportion one mounted. That is why I'm making my own...I've done it before and it's quite a neat process...plus it's fun to make a huge mess!
Trying to figure out a design for my seat...basically I am just ripping off the Laguna Seca style seat. The ones that are available are just a bit too wide at the hump. And I have a ton of glassing supplies around I need to use up.
Here are a couple of shapes:
what do you guys think?
and here is how I plan to mount it...just bend a piece of sheet steel at the same angle as the seat rest, then weld it to the frame, bolt it up. And just have a flat mount across the frame tubes up front.
Here are a couple of shapes:
what do you guys think?
and here is how I plan to mount it...just bend a piece of sheet steel at the same angle as the seat rest, then weld it to the frame, bolt it up. And just have a flat mount across the frame tubes up front.
cierrecart
Been Around the Block
perattzi said:
I like the one with orange, but I'm not sure how it would look on the bike. I really like the ebay ones too, but don't want to wait the month to get it.
Your cutout looks great man.
KrashManhatten
Active Member
Awesome moldin,
also note, man nice old growth maple floors you are working on! I know what the power band of the 350 twin 2stroke is like, I have a 99 banshee (liquidcooled) so it is less flaky, and about 20 years newer.
Slow as a wet week in the lower RPM, but when you hit the PB, it is like you just like you lit the ACME rocket under your ass. keep it in the upper Rs, and get a set of tuned pipes and let that thing go!
cp
also note, man nice old growth maple floors you are working on! I know what the power band of the 350 twin 2stroke is like, I have a 99 banshee (liquidcooled) so it is less flaky, and about 20 years newer.
Slow as a wet week in the lower RPM, but when you hit the PB, it is like you just like you lit the ACME rocket under your ass. keep it in the upper Rs, and get a set of tuned pipes and let that thing go!
cp
cierrecart
Been Around the Block
Hey Perattzi...not sure if you're still having problems getting your brake bled or not. I was having a bitch of a time with my rebuilt caliper, stainless line and new master. No matter what I tried I could not get any pressure. I ended up getting the Harbor Freight version of the mighty vac
and damned if it didn't work in about 30 seconds.
Brakes feel great now.
and damned if it didn't work in about 30 seconds.
Brakes feel great now.
