Yamaha piston ID

[wls]

I have 2 pistons, single ring yamaha, part # 8A5-11631-01-96, these I believe are for a exciter 440, are these standard, or .010 over? thanks

 

[enticeraised]

they usually stamp the top of the piston with a number if its over. eg 10, 20

 

[nysrx]

pistons

They are STD size pistons.

 

[wls]

Nothing stamped on top. thanks guys