03 yz450 valve timing and shim

24 replies to this topic
  • grayracer513

Posted June 24, 2015 - 01:54 PM


Exactly where the header gasket goes; in the exhaust port.

  • Zach Hanson

Posted June 27, 2015 - 10:35 AM


Okay so I was puting everything back together and now the intake can will not move at all when I tighten it down. I loosened it and re tightened it multiple times but it still won't move!
*intake cam

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  • grayracer513

Posted June 28, 2015 - 06:39 AM


Check the camshaft clearance with Plasti-Gage per the manual.

  • Zach Hanson

Posted July 01, 2015 - 10:07 AM


The clearances look good. When you tighten down the cams, are they supposed to be tight or move freely?

  • grayracer513

Posted July 01, 2015 - 10:18 AM


Not valve clearance, camshaft to bore clearance.  It is not uncommon to find that the intake in particular will tighten some with the engine cold.  You should still be able to turn it by hand, though. 


One other thing, and one that really should not affect this question, is that I have always been uncomfortable using the full recommended torque on the cam cap bolts.  The manual calls for 7.2 ft/lb (86 in/lb) with oiled threads.  Oiling threads results in clamping tension that's about 20-30% higher than the standard, clean and dry threads ordinarily specified, and when I run them down that tight, I don't like the feedback I get from them.  So, I use 75 in/lb (6.25 ft/lb) instead, it feels much better, and in the 12 years I've been doing that, I have had no problems.

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