2010 valve cover leak.

7 replies to this topic

Posted March 03, 2010 - 04:45 PM


A friend of mine recently purchased a 2010 YZ450F. After about 10 hours on the bike the valve cover gasket started to leak where it seals around the spark plug hole. The oil finds it's way out of the weep hole in the head and makes a mess. When he took it apart some of the gasket had migrated past the valve cover and head area protruding into the plug hole. He felt that the factory had not taken enough care to make sure the gasket was positioned right causing the leak. After he replaced the gasket all was fine for about 12 hours and now the same thing has happened. He called Yamaha and they said they have not had any similar reports or complaints.

Is anyone else here at ThumperTalk with a 2010 YZ450F experiencing this problem?

  • spdfrks

Posted March 03, 2010 - 04:50 PM


I would clean the sealing surface and the rubber gasket and apply a little Yamabond in that area. I never had problems with the Honda or Yamaha valve covers but the Suzukis would always leak. I started using Yamabond and never another problem. You may also want to check for a pinched or blocked engine breather. It may be pressure pushing the seal out of place.

  • BBrown626

Posted March 03, 2010 - 06:22 PM


There were a few posts on here with the same complaint. Search this forum.


Posted March 03, 2010 - 07:07 PM


There were a few posts on here with the same complaint. Search this forum.

Thanks! I found 04 other posts so far with others having the same problem! From the pictures shown it looks like an easy fix to me. Yamaha just needs to incorporate some vertical positioning tabs on the gasket around the spark plug hole area and I'll bet that solves the problem.

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  • aedwards07

Posted March 04, 2010 - 06:04 AM


Do a search on my name for the threads I posted.I posted it about a month back.There was 5 or 6 of us that it happened to with pictures.

  • DPW

Posted March 04, 2010 - 06:09 AM



  • aedwards07

Posted March 04, 2010 - 07:18 AM


Thanks for that DPW

  • dozza_the_goat

Posted May 22, 2011 - 06:55 PM


Same issue for me. My 3rd just blew. Onto my fourth. Whats up with this?. Not every bike has the issue, as my mates 450f has had no probs. Any ideas why some are giving out?. It cant be the gaskets (bad batch etc), as it would have a wider impact. My mechanic has checked that everything is square, no sharp edges etc, and everything is torqed correctly. Even tried the silicon sealant to be sure. Still no fix. Its now a very expensive problem.....

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