Piston Cylinder size

Ok so i am going to rebuild the top end on my yz125 and what does it mean when the back of the cylinder is stamped with a B?

When the barrel was new, it was measured. There are four sizes of pistons. Yours took a 'B'.

 

If your barrel has never been replated and is still serviceable, a 'B' piston should fit it perfectly. But only if the barrel is untouched since new.

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!


Register a new account

Sign in

Already have an account? Sign in here.


Sign In Now