Yz426 hot cams

4 replies to this topic
  • Gavindobson1

Posted March 09, 2010 - 07:23 AM


I've just re shimmed my exhaust valves however the exhaust cam looks out of time. I have a hot cams auto decomp in and the markers at 9 and 12 o'clock look slightly out. i have tried moving 1 tooth each way but this is even worse.

I have made sure its at TDC.

Intake cam is perfect.

The bike starts first time, would this happen if the timing was out or wouldn't the bike start at all.

I dont want to take the bike out until i get some reassurance.

Any help would be appreciated



  • grayracer513

Posted March 09, 2010 - 08:18 AM


It's normal that the timing marks do not perfectly align. The test is, as you did, to see what it looks like if you move it. If it looks worse, you were right the first time.

This is especially common if you did not replace the timing chain.

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  • Gavindobson1

Posted March 09, 2010 - 04:49 PM


So the engine would not start at all if the timing was out on the exhaust cam.

  • grayracer513

Posted March 09, 2010 - 07:30 PM


It could, but the auto decompression wouldn't work well at all.

  • jcm3

Posted March 10, 2010 - 10:38 AM


Post up after you ride it with both cams. I'm getting ready to do the exhast cam on mine, and know that they say that you won't see the nice power bump until you do both.

Right now I'm fine with the starting help and a slight smoothing out of the power, but am curious how it feels after adding both cams in.

Good luck.

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