xr80 PLEASEREAD

[cr25096er]

is it worth getting an xr80's crank rebuilt? the rod has side to side play and i can wiggle the main bearings side to side with the crank out of the cases. the bike before i tore it down would run badly n break up and pop n backfire. it also ran unconsistantly reving up and down but i suspect it had an airleak and it always had a wierd sound from the lower end. the compression it good and valve seem fine cam chain n sprockets are fine cam lobes r fine rockers are good. cylinder is good. i need a clutch or at least the gear behind it and a crank or crank rebuild. please help me this is my bros bike and it will be my play bike. i suspect also the points could be off. how do i set them? i really dont want 2 sink $ into it if im just doing things and experimenting w/ a $200 crank and $100 clutch and lke $100 worth of gaskets. could an air leak on the intake like just after the carb cause the crank to go? i also ahve a service manual.

 

[Gary B.]

What year and what condition is it in? :confused: An air (vacuum leak) on a four stroke won't cause lower end problems as they will on a two stroke. It'll just give you performance problems such as a poor or no idle, and a hesitation. Also, I wouldn't think of rebuilding ANY motor without a manual. :uh:

 

[cr25096er]

its an 86xr80 and its in ok condition but has been riden a lot.

 

[Gary B.]

Boy! That's definitly a judgment call. I'd have a hard time investing serious money into that old of a bike. Just buying a manual may cost more than the bike is worth. Be warned! It's way to easy to get "upside down" in a hurry when fixing up any old vehicle.

 

[cr25096er]

yep i hear ya. but all it needs is a crank n clutch but they are expensive. i guess ill think about it. also if ne1 has xr80-100 parts trhey are selling tell me.

 

[Stew312]

a little bit of side-to-side play with the crank is ok, its up and down play that you have to worry about. As for the popping and backfiring, that sounds to me like the timing is off.. Check the magneto, and you might have to get new points and a condenser.. Those aren't expensive though, should be under $10..

 

[cr25096er]

i can when holding the crank wiggle the main bearing as if i was holding the bearing in place and rocking the crank that is on both of the mains. on the rod their is side to side but i havent measured it to see if its out of spec but i do think it is. on the clutch i broke 1/2 of a tooth on the gear behind it. do u think i can get away w/ leaving thae clutch alone? how do i put pictures up on drn? thanks