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Thread: XC4 valve adjustment - exhaust side rocker arm pin stuck

  1. #1

    Default XC4 valve adjustment - exhaust side rocker arm pin stuck

    Hi everyone,

    Itís my first time doing a valve adjustment on my 2008 450 excr. It has 150h/4000miles on it.

    The problem Iím having is with the exhaust side rocker arm pin. The intake side came out very easily but the exhaust side seems to be stuck on something. I found a forum post on thumper talk that seems to be relevant. (https://thumpertalk.com/forums/topic...-rocker-shaft/) It seems like this guy had a similar problem but it doesnít seem like they found out why itís stuck.

    Another thing is that all the valves are out of spec but the gaps are bigger than theyíre supposed to be (from manual itís 0.12-0.17mm for exhaust, 0.1-0.15mm for intake) mine measured:
    exhaust - 0.23mm, 0.2mm
    intake - 0.18mm, 0.2mm.
    Is this common? I thought the gap was supposed to get tighter with engine wear...

    Any help would be appreciated!
    Attached Thumbnails Attached Thumbnails 2415D401-0C15-47AE-985C-7249EADA5A36.jpeg   BEDABDD2-1137-4247-A4FA-1121D857E766.jpeg  

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  3. #2

    Default Re: XC4 valve adjustment - exhaust side rocker arm pin stuck

    https://youtu.be/wkfN3rS1jWc

    Hereís a video of whatís going on. Sorry for the heavy breathing in the background.

  4. #3

    Default Re: XC4 valve adjustment - exhaust side rocker arm pin stuck

    Did you figure this out? I'm having the same issue.

    2008 450 exc-r with ~7800 miles. Front rockers weren't really moving. Tried taking the rocker pin out and it's very stuck.

    Ordered a slide hammer and will try with that when it arrives.

    Also, my 3/4 of my gaps increased to about 0.28 mm, the last stayed at 0.15mm. Last I checked them, all were about 0.15mm.

  5. #4

    Default Re: XC4 valve adjustment - exhaust side rocker arm pin stuck

    Used this slide hammer and got out the rocker arm pin. Not sure how it got such a huge gouge, but that's definitely why it was stuck.

    Attachment 37796

  6. #5

    Default Re: XC4 valve adjustment - exhaust side rocker arm pin stuck

    I don't have the option to edit my comments, and the attachment link no longer works...here's another upload:
    https://i.imgur.com/wMh1lso.jpg

  7. #6
    KTMTalk Member KTM64's Avatar
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    Default Re: XC4 valve adjustment - exhaust side rocker arm pin stuck

    If you get this sorted, put the 125 oil jet in the right case half for more oiling and the updated rocker shafts for better oiling up top.

  8. #7

    Default Re: XC4 valve adjustment - exhaust side rocker arm pin stuck

    They redesigned the rocker shafts, with a flat spot on top to retain oil, flat spots go up

  9. #8

    Default Re: XC4 valve adjustment - exhaust side rocker arm pin stuck

    Quote Originally Posted by spud786 View Post
    They redesigned the rocker shafts, with a flat spot on top to retain oil, flat spots go up
    Quote Originally Posted by KTM64 View Post
    If you get this sorted, put the 125 oil jet in the right case half for more oiling and the updated rocker shafts for better oiling up top.
    Do you have part numbers or links?

  10. #9

    Default Re: XC4 valve adjustment - exhaust side rocker arm pin stuck

    Rocker arm pin came in...on install I realized that the rocker arm itself has a manufacturing defect (small bulge) on the inside, which caused the damage to the rocker arm pin. $90 and another week waiting for it to come in

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