os 91 ring in a ys 91 st

[chrsvct]

Has anybody tried an os 91 ring in a ys 91 st, they are the same bore (27.7 mm), but I dont know about the thickness of the ring itself, I ordered one from tower to try, I was just wondering if anyone had tried it, cant seem to find a ys 91 st ring and the 91 sr is a 27mm bore so it wont work either

Thanks,

Chris

[DavidH]

Don't know about the 91's. But from past experience with YS and OS motors the rings are different on the same size motor.

David

[chrsvct]

the os 91 fx piston ring (part # 29503400) is almost an exact replacement for the ys 91 st, the thickness (od to id) is about .001" thicker than the ys ring, but other than that they are identical.

Chris