Valve shim help

I started to shim my valves on my yz and when I tighten down the end bolts to exhaust cam does not want to spin

Either the valve bucket to cam lobe clearance it too tight, or there is an issue with the cam or the bore where the cam rides on

Be sure that the cam caps are seated by hand all the way down; never pull them down with the bolts.  Be certain to tighten them in 3 or so steps, in the sequence shown in the manual, and not one tick tighter than spec.  In fact, tighten them to 75 inch pounds instead of 86.


Check clearances with plasti-gage as shown in the manual.  Not too unusual for the intake cam to feel a bit tight in a cold head.

It was a burr that was holding it . I sanded it and it is fine

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