YZ 125 top end rebuild
I'm looking at buying an '86 YZ 125 real cheap. It runs fine right now, but his buddy told him it will probably need
a piston and rings soon. My question is if the rings are worn, why would it need a piston too? And, if it needs a piston, wouldn't it need to be bored (if not oversize already)? Last, how difficult is it to rebuild the top end, I'm an automechanic, but haven't worked on bikes for about 16 years! Thanks for any advice.