durangodog
Member
- Jul 15, 2008
- 1
- 0
ok, so i have a 2001 yz250. after piston ring failure and cylinder damage, i had it overbored to a 265cc, which i believe is a .020 over. about half a year later, one of the crankshaft bearings let loose and a piece got into the cylinder and tore everything up again. at this point, after replacing the crankshaft bearings, i would prefer to buy an OEM cylinder and piston in hopes of having a more reliable motor. my concern is that the power valve was modified to fit the overbore setup, and i'm not sure if it can be run with the stock cylinder/piston without performance issues, i.e. throttle response, bogging. clearance between piston and power valve isn't an issue, as the valve fits the larger bore. maybe its nothing to worry about, but since the new OEM cylinder and the repair on the old one are roughly the same cost, i believe i will go back with the overbore before i buy a new power valve. thanks for the help.
