engine rebuild? where to find parts?

[gearhead16]

hello, first post on this forum

i have a 1981 xs400, hardtail, custom exhaust, custom bars, and paint, nothing special will post pictures if your curious soon!!

i am having trouble finding the parts i am looking for, the ugliest part of my bike is my old corroded oily engine, and i have picked up a previously running engine in good shape off craigslist. i began to look online for parts and found its hard to find what im looking for.

and im also curious if you can put 650 jugs, heads and pistons on a 400 bottom end.

i am looking for a complete rebulid kit, would use stock crank and rods, more or less looking for pistons(forged, or i guess cast.}, bearings, rings, clutch kit, different exhaust options?
gaskets and seals.

if anyone could help me, or let me know im looking for things that dont exist that would be helpfull.

thank you
zack

 

[xschris]

Xs650 engine parts will not fit. Not much engine stuff for these bike anymore. There is a guy on ebay that sells new standard size piston rings and a complete gasket and seal kit. You can try to google the part numbers of stuff you may need or try and see if your local yamaha dealer still has anything left over. There is a german website that has new oversize piston kits but the price with shipping to the states is over $400 just for pistons rings and wrist pins. After you get gaskets, seals and send the jugs out for boring ( not to mention if the valves need work) you can buy another good running bike for the money you will spend

 

[Unkle Crusty]

I did that on a BSA A7 500. Put A10 650 cylinders on it. Got Hepolite pistons Hamilton rings. Laced on new rims, painted the frame tartan red, polished the alloy fenders.
Maybe a seat cover from kangaroo skin and put a Triumph chrome tank bag holder on.
Got the cam built up with stelite, and reground to rocket specs. Those were the days.

Machine shop I went to earlier this week charges $95- per hour.

Unkle Crusty*

 

[gearhead16]

Xs650 engine parts will not fit. Not much engine stuff for these bike anymore. There is a guy on ebay that sells new standard size piston rings and a complete gasket and seal kit. You can try to google the part numbers of stuff you may need or try and see if your local yamaha dealer still has anything left over. There is a german website that has new oversize piston kits but the price with shipping to the states is over $400 just for pistons rings and wrist pins. After you get gaskets, seals and send the jugs out for boring ( not to mention if the valves need work) you can buy another good running bike for the money you will spend

What about the xs650 engine itself? Does it bolt up, obviously im looking at some fab work, but how far off would i be? Whats the bang for my buck in my situation, riding days are over for me for a few cold snowy months

 

[TimBuz]

Theres a build thread on here where a guy shoe horned a 650 engine into the 400 frame, but im pretty sure it was alot of work. I think alot of people have thought about engine rebuilds on here but it seems too costly to find pistons/rings or anything oversize. Theres always been talk of using pistons from other bikes (i think it might have been a GPZ or something) and I did see a thread where one guy has claimed to have over bored and used one but gave very little information on it.

Bang for your buck is probably what everyone else is doing, find a good running 400 engine and look after it. Keep your build as low cost as possible, enjoy your bike for a while and sell it on to recoup costs. Theyre a cool bike for what they are, nice lines, cheap, but like everyone has said parts for engine rebuilds are hard to find and expensive. Im just waiting till someone with the time and skill tries a different piston ring combo from another bike and gives us a definitive answer on what will work

 

[Unkle Crusty]

These DOHC bikes make about 45 horsepower and weigh about 375 pounds, with a single disc up front and a drum at the rear.
For a bit more money, and SV650 Suzuki makes 650 to 70 horsepower, weighs 375 pounds, has two discs up front and a single at the rear. There are lots of mods, and go fast gear available.
I used to have an SV650.
I have collector plates on my XS11 Yamaha. I need somethings else insured at the same time. The XS400 is much cheaper to insure than the 650. In the spring I switch the plate from the XS400 to my SV1000 a pay more $$ for the summer months.

Cheapest way to get a faster bike, is to buy a faster bike.

Unkle Crusty*

 

[FarmBoy72]

Theres a build thread on here where a guy shoe horned a 650 engine into the 400 frame, but im pretty sure it was alot of work. I think alot of people have thought about engine rebuilds on here but it seems too costly to find pistons/rings or anything oversize. Theres always been talk of using pistons from other bikes (i think it might have been a GPZ or something) and I did see a thread where one guy has claimed to have over bored and used one but gave very little information on it.

Bang for your buck is probably what everyone else is doing, find a good running 400 engine and look after it. Keep your build as low cost as possible, enjoy your bike for a while and sell it on to recoup costs. Theyre a cool bike for what they are, nice lines, cheap, but like everyone has said parts for engine rebuilds are hard to find and expensive. Im just waiting till someone with the time and skill tries a different piston ring combo from another bike and gives us a definitive answer on what will work

AGREE! best bet is to find a running bike and grab the engine. I was able to get a 77 xs400 for 175 bucks, wasn't pretty but engine was solid. Had mag wheels that I wanted, even came with a bent fork! For awhile I was watching the local craigslist and bought a total of 3 xs400s, only really have one good spare engine.

 

[Unkle Crusty]

I have a spare engine too. It is the original motor and a 6 speed.
New engine in the bike is the same DOHC, and a 5 speed. I will rebuild the 6 speed one day.

Back to the XS650. The only redeeming quality they had was, they did not leak oil. They did not handle very well, and they vibrated. The Japanese found out the same thing as the British. If you bumped up a smooth running 500cc motor to 650 it would start to vibrate. Bump it again to 750 and 850, as Norton did, and they shake like a bastard. So Norton rubber mounted the whole thing. A disaster in my opinion. I have owned some of the above and been on all except the XS650.

Yvon Duhamel the flying frog, had to ride one in the production class, as part of his Yamaha contract. He rode the Yamaha 250 and 350 GP bikes. He deliberately dropped it in the esses at the Westwood BC track. I was there.

Further, most of the XS650s do 120 mph in the minds of ex owners. Another fantasy.
On a tight track a good running and handling 400 was a good match.

But that is just my opinion.
Unkle Crusty*

 

[gearhead16]

Thank you guys!! Ill just clean my engine a d try to find my mysterious oil leaks!!