1 size piston, 2 sized cylinders

[wornknobby]

on my 90'cr125, there are 2 different sized cylinders, an "a" and a "b". now wiseco has a one size piston that fits both cylinders. my question is, if the cylinders are in good shape, is it better to run the "b" cylinder so the clearence is tighter, or the "a" cylinder so there is more clearance but less friction?

 

[MOTOX888]

Do some searches and see how much a piston will expand when the motor is at operating temperatures. Too little clearance, and a piston that expands too much will cause it to seize. Too much clearance and you have the risk of braking the piston skirt

 

[wornknobby]

well, i ran a wiseco w/ the "a" cylinder all last season and i worked good. but i thought that maybe it would benifit more from a more tighter fit, since this piston is also supposed to fit the "b" cylinder. if it wouldn't worked i don't think they would just use one size.

but i don't know which choice is a "wiser" one???

 

[Faded]

The difference between the two is 0.0005"...pick one and run it.