Crankshaft cam chain sprocket wear

3 replies to this topic
  • tribalbc

Posted November 08, 2010 - 11:39 AM


I'm rebuilding my 450+ hr motor on my 07 WR450. I pose the quetion here hoping Grayracer will reply....
First thought's was I was going to be replacing the crank with this many hours but everything is in the tight end of spec and looks great.
Only wear I'm seeing is the cam chain sprocket teeth have 3 visible marks on each tooth were the chain rides. With a dental pick it still feels smooth though, no ridges and otherwise the teeth look fine. Thoughts? Replace, or good for one more year?

  • grayracer513

Posted November 08, 2010 - 12:02 PM


You should be OK as long as the tooth profile hasn't been changed by a significant amount of wear.

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  • kx250fnick

Posted November 08, 2010 - 12:11 PM


You should be fine,but again if your not sure, its a good idea to replace that kind of stuff.

  • tribalbc

Posted November 08, 2010 - 02:55 PM


You should be OK as long as the tooth profile hasn't been changed by a significant amount of wear.

Thanks Gray :p
Tooth profile looks good, so I should be good to go.
Pretty amazing these motors if you take care of them. Bike has over 450hrs, with 3yrs of offroad racing and lot's of riding at the MX track. Cylinder is still well within spec, and I have only adjusted 2 intake valves once and they still haven't moved from the one adjustment 100hrs ago :thumbsup:
I will do the valves anyways as I think they are living on borrowed time, piston and cam chain. I'll do the bottom next year, save a little hurt from the pocketbook right now.

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