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Ty250a engine

Posted: Fri Aug 14, 2015 8:06 pm
by TayIpsilon
Hi. Am buying a motor and will be checking it out. I know the best way find a chassis for it to surely be to find that its stuffed. What would a rolling chassis likely set me back and am i three decades too late? Not the first time i've been late to a party and its a pipedream so far, but thought i'd ask. Will the A motor slot in all twin shock frames, and any common pitfalls to be aware of with the engines?

Ta muchly, glen.

Re: Ty250a engine

Posted: Fri Aug 14, 2015 9:12 pm
by David Lahey
There are plenty of unloved TY250s including rolling frames still out there. Your A model motor will fit in any of the TY250 twinshock model frames. If you want to fit it in something different and don't mind a workshop challenge, look for full-sized twinshock-era trials bikes that have twin front downtubes (KT250, OSSA, late model Montesa) or another option for people who love frame mods would be to use a Bultaco frame and make the front downtube into two. There are lots of unloved Bultaco frames around.
TY250 motors don't have any particular weaknesses. Any motor that has been sitting around unused for a long time would be likely to have some corrosion on the bearings that might show up in a disastrous way at some point after it gets used again. Any 1970s two stroke motor that hasn't been rebuilt since new will have problems with the crankshaft seals leaking. You can probably expect that the clutch plates will be stuck together, and will (at least) require disassembly one-by-one to get them free again.
Also there is always the question about why the motor is not in the bike it came from.
TY250 rolling chassis with rusty forks, bizarre frame mods, rusty spokes, dented tank, bashplate missing, seat missing and crap shockies probably $100 - $200

Re: Ty250a engine

Posted: Sun Aug 16, 2015 12:44 am
by TayIpsilon
Thankyou david. At 1-200 dollars, i'll keep my eyes open for one. Motor is good as far as i can see in the top end (bulk compression) and i shall probably split the cases and inspect the guts as its an unknown quantity, or at minimum clutch cover off. Is it worth putting an ad on the site asking if someone has a rolling chassis do you think?

Re: Ty250a engine

Posted: Sun Aug 16, 2015 10:56 am
by David Lahey
Wanted ads, Gumtree, swap meets, eBay, talk to likely people at vintage motorbike events and vintage machinery festivals. Whatever you can think of.
I've had success at finding bikes by riding an old bike or displaying it at places like machinery shows and swap meets. People come up and either tell you they had such and such when they were young, or what they have at home, or what their mate has in his shed.

Re: Ty250a engine

Posted: Sun Aug 16, 2015 11:08 am
by David Lahey
Rockhampton bike show might be a good spot. Lots of old stuff being displayed and lots of motorbike people attending. Saturday 29 August.

Re: Ty250a engine

Posted: Wed Aug 26, 2015 4:13 am
by TayIpsilon
Well, pulled the clutch cover and after a bit of a peruse theres a broken spring on the claw that drives the shift drum. Jury rigged it and we have all gears. Clutch frees off, and bar being dirty, nothing so far seems wrong.

Will put up an ad afterall. Thankyou.