09 YZ450 transmission problem

2 replies to this topic
  • Madg11

Posted September 10, 2011 - 01:32 AM


Hi guys,
My 09 YZ450 is feels like it jumping the gear in 5th under power. I feels like the chain is jumping the sprocket (its definately not) thats about the only way i can describe the issue. I have been getting alot of false neutrals and the issue is getting worse, both neutral and the jumping.
I cant use 5th at all Really.
Any help or advice would be greatly appreciated.

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  • grayracer513

Posted September 10, 2011 - 08:06 AM


The locking lugs on the sides of the 3rd and 5th gear pinions (gears on the main shaft) are rounded from wear, and no longer have the undercut on them that makes them hold in under power. The force of the gears pushing apart from one another will have also bent the forward shift fork, so at minimum, both gears and the fork will need replacement.

Check the bearings carefully, particularly the left side main shaft bearing.

  • Madg11

Posted September 10, 2011 - 11:42 PM


Thanks for the advice. I have been told this is a common problem with the later model YZ's, does this sound right?
Would replacing the gears give me any kind of extended use? I do trail riding only and do like the the motorcrossers, but might be better on an enduro?
Thanks again for the help.

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