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Strange Issue: Valve Related

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Hi all!

I own a 2006 CRF250R. Excellent bike, no troubles at all. A friend of mine has an 04 that has recently had issues starting. He called me over to take a look at it and it will only start if you bump it. He then states that he has never checked/shimmed the valves since he purchased the bike new in 04....

So, seeing how I have shimmed these bikes before (had an 05), I offerred to do it for him.

Get it home, here are the specs:

RI- .0010

LI- .0025

RE- .004

LE- .004

Yikes.

So I shim it up as best as possible, using the spreadsheet that I found on this forum a while ago. Got the LI at a perfect .005 and the RI was still a little tight at .003. The LE came up to a .009 and the RE was at .006.....

Just to see how it ran, I put it back together and started it up. Started first kick but it had a crazy tick to it. Took it back apart and reshimmed. Both intakes are now a perfect .005 and the LE is up to a .010. However, no matter what I do, the RE stays at .006. Time for valves, I know.

However, when I put it back together for a second time to start it up (keep in mind I did not remove the came after the first start up, I only had to fix the exhausts) it won't start. It feels like the auto-decomp is sticking because the kick starter has a weird action to it. I'm stumped.

HELP PLEASE

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Probably the cam chain tensioner. Back it out a few turns and let it "spring" back into place. Did you remove the tensioner? or back it out with a screw driver or special tool? Every time I've removed it I need to do the obove operation or it creates a lot of drag when you kickstart.

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Timing is good.

I've heard that before. Re-check timing and be sure you released the tension on the cam chain adjuster before you installed it.

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Used a screw driver to back out the adjuster and held it in place with a pair of vice grips. Then I zip tied the cam chain to the frame and removed the cam cap bolts, then the cam caps, then the cam. Shimmed, re-assembled, then removed the screw driver- confirming that it was turned completely counter-clockwise. The marks I made on my chain and cam sprocket line up, and the marks on the cam line up with the head. Could the chain have skipped a tooth on the sprocket in the case?

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Used a screw driver to back out the adjuster and held it in place with a pair of vice grips. Then I zip tied the cam chain to the frame and removed the cam cap bolts, then the cam caps, then the cam. Shimmed, re-assembled, then removed the screw driver- confirming that it was turned completely counter-clockwise. The marks I made on my chain and cam sprocket line up, and the marks on the cam line up with the head. Could the chain have skipped a tooth on the sprocket in the case?

don't go by marks on chain--- only on cam gear/ head with coresponding mark on timing gear which must be right on or easy to be off a tooth---see 'sticky' with pics.

http://www.thumpertalk.com/forum/showthread.php?t=179775

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