valve adjustment

3 replies to this topic
  • YZGazza

Posted December 29, 2009 - 08:27 PM


I just had a crack at adjusting my valves for the first time and everything seems straight forward and not too complicated. I checked the clearance and all the valves were out. The intake valves were only a little out(all .12 when they need .15-.20) and the exhaust were a little further(.15 and .2 when they need .25-.3) I worked it out and changed the shims smaller and the intake valves turned out right but the exhaust ended up with less clearance than in the beginning. I dont get how this happened when the shim i put in is smaller than the shim i took out?

  • grayracer513

Posted December 29, 2009 - 08:45 PM


... the exhaust ended up with less clearance than in the beginning. I dont get how this happened when the shim i put in is smaller than the shim i took out?

The possibilities are:
  • The exhaust valve(s) were not entirely closed when you "read" the clearance the first time because of a bit of carbon holding it open
  • The shim you installed is not entirely seated on the valve stem. Sometimes they can become tilted in the bore in the spring retainer and become wedged, giving an incorrect read.

Be sure you are at TDC, and lightly tap the top of the lifters a couple of times, then recheck the clearance.

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  • YZGazza

Posted December 29, 2009 - 10:51 PM


Thanx mate, I had tried to install the shim and lifter as one with a magnetic rod and none were in the bore square. I did them seperately and made sure they were perfect. The intake are better and the exhaust are very close. I'll get some diff shims in the morn and put the head back together. Will the clearance become less every time the valves need adjusting or can it go either way?? If the manual says exhaust .25 -.30mm which end of the scale is best? My exhaust are at .25 and .23mm. Intake says .15-.20mm and mine are all .17. Cheers

  • grayracer513

Posted December 30, 2009 - 09:12 AM


Generally, clearance closes as the valve face wears. By your exhaust valve clearance, I assume your engine is an '00 or earlier with stainless valves. If it's a later engine, you should not go more than .10mm smaller than original on the shim sizes without seriouly considering a valve replacement.

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