stripped compression release threads on cylinder head

3 replies to this topic
  • potroast1999

Posted September 02, 2010 - 08:15 PM


02 YZ426-Just finished rebuilding motor and must have over torqued the compression release bolt on cylinder head. Ran bike for about 30 minutes and noticed some oil spitting out. Traced back to loose compression release bolt. When I unscrewed it, noticed that the about half threads on cylinder head were stripped. Still enough left to bite, but not to tighten to spec without ripping all threads out.

I only use the compression release lever on the rare occaison that I flood the engine. Pull and kick a few times. Otherwise never use it to start (have hot exhaust cam with auto-decompression)

Question: Since I rarely use decompression level, can I just wrap bolt with some liquid steel fasten to cylinder head and let set up and just leave it like it is to secure decompression shaft and seal stripped hole?

  • cowboyona426

Posted September 03, 2010 - 07:09 AM


I would heli-coil or time-sert it and see if you can find one of the plugs that allow you to remove the decomp mechanism altogether. There used to be a guy on the site that sold them (Vibeguy) but I don't know if he still does or if he's even still a member here.

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  • grayracer513

Posted September 03, 2010 - 07:54 AM


If you remove the shaft and the original seal, you can plug the hole with an 18mm freeze plug from an auto parts store for less than a dollar. Then you can tap the hole to the next upward size and put more or less any bolt in there.

  • potroast1999

Posted September 03, 2010 - 03:34 PM


Thanks guys. Found the freeze plug and will be tapping tomorrow.

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