messed that up. i currently have a 102mm piston and need to redue it. i dont want to go to a 727 so what do i have to do? is there a 103 or 102 1/2 size piston? i would think it would cost alot of money to resleave the cylinder and rebore it. any ideas?

 

Welcome to the real world. Where I come from people never bored thier engine out unless the cylinder walls were unfit for use, none of this "lets bore the engine out to its tolerances for 1 hp" crap.

You willl need to have the cases machined and install a new sleeve into the bike and that sleeve can be bored to whatever size you desire. I dont see why you couldnt have a 102mm sleeve if you want to use the same piston and just re-ring it.