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2009 kx250f intake cam

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My bike felt really sluggish on the track one day and then died and would not start. I pulled the head off and my intake cam had completely worn a whole in one of the valve buckets and one of the lifters is worn down and squared off. Can anyone help me figure out what happend and why it only happened to one valve? Everything else looks good I have not pulled the valve out yet but I can push it down a little with my thumb. And also the bike has a 270 kit idk if that makes a difference or not. Thanks guys!

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No idea what would cause something like that to happen, but it may have originated in the "can push the valve down a little with my thumb" thing. You shouldn't be able to even begin to push that valve down with your thumb, sounds to me like you have a very weak or broken valve spring along with (and possibly causing) the cam/bucket issue.

Have you posted this down in the KX250F forum?

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No idea what would cause something like that to happen, but it may have originated in the "can push the valve down a little with my thumb" thing. You shouldn't be able to even begin to push that valve down with your thumb, sounds to me like you have a very weak or broken valve spring along with (and possibly causing) the cam/bucket issue.

Have you posted this down in the KX250F forum?

when I push it its still really really hard and I can barely get it to move and no not yet I will right now

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Had the exact same thing happen to a jeep motor a few years back. Cam lobe was wore to almost round and lifter was wore down probably 1/8 inch. Never could get a straight answer from anybody about what could have caused it.

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It looks like you may have been at zero clearance, so the shim was not high enough to support the bucket.  As the lifter hit the top of the bucket, it caved it in relative to the spring retainer.  Either that, or the top of the valve stem wore down and caused the same thing.  You can see where the bucket took the shape of the retainer.  Pretty cool that it didn't cause a boat load of damage.   :applause:

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