Valve check help


4 replies to this topic
  • CheYuen

Posted October 23, 2015 - 09:46 AM

#1

I have a 2005 WR 450 and am attempting to check the valves. 

 

I have aligned the timing marks:

20151023_104611.jpg

 

which orients the camshaft dimples like this:

20151023_104919.jpg

 

and the cam lobes like this:

20151023_104806_1.jpg

 

At this point I have no clearance.  Per the manual, I rotated the crankshaft one turn which makes the cam lobes point different directions, the camshaft dimples not even with the crankcase, and the timing mark unseen. 

 

Which position is correct to check valve clearance?


Edited by CheYuen, October 23, 2015 - 11:34 AM.


  • grayracer513

Posted October 23, 2015 - 09:57 AM

#2

The cams rotate at half crankshaft speed, so the engine takes two full revolutions to complete a cycle.  The correct clearance and timing check position is at TDC on the compression stroke, which places the lobes pointing "up and out",  away from the lifters.  (Flickr is blocked where I work) 

 

If you have no clearance in that position, it's a fair bet that you need a valve job, but you can reshim it and see how things work out.  It will certainly require more than a .10mm reduction in shim thickness if you are at (or below) zero, and that's already a bad sign.  If you reshim to specs, check the clearance again after you run for about 2 hours.  If you then find that the clearance has already decreased, you need new valves.



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  • stevethe

Posted October 23, 2015 - 09:30 PM

#3

I have a 2005 WR 450 and am attempting to check the valves. 
 
I have aligned the timing marks:
20151023_104611.jpg
 
which orients the camshaft dimples like this:
20151023_104919.jpg
 
and the cam lobes like this:
20151023_104806_1.jpg
 
At this point I have no clearance.  Per the manual, I rotated the crankshaft one turn which makes the cam lobes point different directions, the camshaft dimples not even with the crankcase, and the timing mark unseen. 
 
Which position is correct to check valve clearance?


You are not on compression stroke. The cams must face out when you are on compression stroke. You are one full turn off on your crank.

  • CheYuen

Posted October 26, 2015 - 04:36 AM

#4

Thank you grayracer513 and stevethe.  I'm not sure how I bungled that even after re-checking.  Intake and exhaust clearances are on the snug side but within spec.  I will most likely re-shim next go round.  Thanks again.



  • bikedude987

Posted October 26, 2015 - 06:04 AM

#5

*EDIT* I said something stupid, ignore me  :facepalm:


Edited by bikedude987, October 26, 2015 - 06:06 AM.





 
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