Clearances help

6 replies to this topic
  • mrz1000

Posted February 08, 2014 - 03:49 PM


I just checked clearances on my new to me yz400f never done this befor, all are within spec accept one of the intake valves it was at .130 mm instead of what it was supposed to be .150-200mm I feel like 1 valve out that little bit isn't a huge deal but befor I put it back together I want your opinions plz. Thanks.

  • 2012 450 xc-w

Posted February 08, 2014 - 04:55 PM


Just me, I would take it back apart and put the one valve back in spec........

  • grayracer513

Posted February 08, 2014 - 04:59 PM


Shim it.  Just go one size down and be done.

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  • 72degrees

Posted February 09, 2014 - 03:40 AM


I would always adjust if even only one valve is tight. One a tiny bit loose I might think twice. It's not as bad as it seems if you have never done it before. Even an old gimmer like me managed it once I had rigged up a really bright light and dug out the super magnifying spectacles.

  • NitrousR1

Posted February 09, 2014 - 08:01 AM


You allready did half the work. Just shim it and ride on

  • mrz1000

Posted February 09, 2014 - 02:54 PM


Thanks I will shim it down a size

  • grayracer513

Posted February 09, 2014 - 07:38 PM


One thing that you have a very good chance of finding is an "odd sized" shim under that bucket.  The shims listed in the manual and sold over the counter are in increments of .05mm.  But the assemblers at Yamaha use shims in increments as small as .01mm, so it isn't unusual to find shims marked 178, or 183.  Gums up the math a little is all.

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