Need Help with setting valve clearance

3 replies to this topic
  • racerx121

Posted February 02, 2010 - 12:18 PM


I have a 2005 yz 450. The craftsman feeler gauge I have only goes down
to .178 so I am a little ill equipped. The .178 fits under the exhaust valves and the shims are 188, 191 and 189 so I was going to drop down to a 185.
This would put me in the .20-.25 spec but the .178 feeler gauge does not go under the front intake valves. The last time I checked them the .203 fit under them. Another issue I am having is the front shims numbers are missing on one valve and it looks like 53 on the other so I am assuming its a 153? Any idea on what came stock on the shims on this bike? I am the original owner and I have never changed the shims.

Also I am looking for advice about buying the hot cams shim pak? What is the O.D. of my shims? Do the Honda or Kawasaki shims fit my bike?
I think the Hot Cams shim pack would be more cost effective.

Thanks for any help.

  • racerx121

Posted February 02, 2010 - 12:19 PM


I made a mistake on notating the correct measurement for the intake valves. The last time I checked them with another gauge the .127 fit under them.

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  • Mike546

Posted February 02, 2010 - 12:47 PM


Your best bet is to buy yourself a set of feeler gauges and a micrometer, it will make life much easier. Otherwise your just guessing.

  • grayracer513

Posted February 02, 2010 - 01:21 PM


We need to back up a little here.

To begin with, the three valves on the back of the head are the intakes, and the two at the front are the exhaust.

Secondly, do your brain a favor and round the metric equivalents marked on your English gauges to two places (.178 =.18 on your .007" gauge, for instance)

Then, keep in mind that the shim sizes are marked without a decimal point; a 188 shim is 1.88 mm thick, for example.

So before we get started here, go back and get the right measurements for the valves again, this time calling them by their correct names, so nobody gets crossed up in the process.

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