This is an area I've never had to deal with before: Does anybody know if TZ250-G shocks can be rebuilt? I've heard that they can't, but haven't heard a technical reason why not. If the bike I'm building turns out to have a leaky shock, what are the options? Find an original in better shape ( seems unlikely). Are there reproductions or alternate parts available?
FYI I had asked a friend of mine who works for Yamaha about this very subject. Unfortunately, his reply was as follows: "Well Rick the answer is no. There never were any internal rebuild parts available only external bolts and the bushing for the clevis pin. Sorry. It's possible that one of the race suspension outfits like Noleens would have experience and access to some parts but I don't know that for sure."
Well, there might be hope for the seals, if the ID and OD aren't something too odd. I know there are outfits that will rebuild obsolete shocks, provided they can come up with seals. The other possible dilemma I was wondering about was whether it lends itself to easy disassembly/reassembly. Some shocks practically have to be sawed apart, and aren't really rebuildable for that reason.
Adapt a modern shock. Make a bracket that bolts to the original front mount and at the back end a couple of tubes running to the original frame tubes. ORRRR..... I bet Works Performance could create something. Ray
I'm somewhat limited because this bike is a Mutt. It has an RD400 engine, so there's no room for a shock with significantly larger diameter.
I think Works is still your best bet. The stock yam damping and spring rate is probably the equivalent to one shock from a late 70's RM or CR . How long is the stock yam shock? Works makes stuff up to app 18" as a matter of course. Ray
Actually they can be rebuilt, just takes a shaft clamp and a piece of tubing/pipe to take one apart. The big problem might be the seal but it would not be to hard to make a new shock cap to mate with an available seal (shaft size should be a common size) If you rebuild it you should consider removing the internal piston/nitrogen chamber, this will increase the amount of oil. When you do this you add an external reservoir, this can also give you compression adjustment. As far as the piston ring goes, if you measure it there may be a replacement available from some std current shock that can be adapted or you should be able to get one machined. as I remember it the ring is sort of a phenaulic material any shock that has a screw on top mount like an ohlins can be adapted, I have seen one for a TZ750, it is a threaded cap that has about a 1 inch diameter extension to the top eye/mount to give it the proper overall length.. It has been a while since I was in one, my E-mail is [email protected] if anyone wants to know the details of disassembling and re-building one.. Bob
what the... ??? What the heck is that supposed to mean, Scott? I suspect it means you had too much champagne after winning that race and it hasn't worn off.
it means i should read my post before i submit it! it should have read something like "you are a mutt". just trying to keep your post near the top.
Carl, I've got 2 acquaintances in the suspension biz up here, both trustworthy. I'd be willing to bet like Yamaha Fan said it can be rebuilt with a little imagination. I'm coming down in a day or 2 and if you want I'll bring it back with me get one of them to check it out for you.
I dont know if this will help?A racer just posted a shock for a 92 tz on the rpm web site.Sorry but i dont know anything about your bike(yr) or even if this will work.But its new!Hope it helps. www.RPMRACECLUB.com Steven #1 vintage 6
I'm gonna try and get the thing running in the next few days. Once I know it runs, I'll worry about the shock. Maybe I'll send it back with you after CMP. What day are you stopping by the house?
Most likely Thursday but maybe Wednesday. I'm MX'ing in Bunnell tonight and going out with my buds whichever night I don't come down there but we haven't finalized the day yet. I'm gonna bring my spare tranny back down to do some comparison with the parts HB brought over.
