Valve shim help

3 replies to this topic
  • guccimanescarwash

Posted July 30, 2014 - 11:57 AM


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

  • DC_Excitement

Posted July 30, 2014 - 04:06 PM


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

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  • grayracer513

Posted July 31, 2014 - 05:54 AM


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.

  • guccimanescarwash

Posted July 31, 2014 - 09:19 AM


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

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