Cam Timing Help Please


3 replies to this topic
  • cbesing

Posted December 02, 2009 - 07:31 PM

#1

At TDC the ex mark was one tooth counter clockwise when the In mark was at 9.

I released the chain tension and rotated the ex cam one tooth and now they align at 3 and 9 but when i add tension the TDC alignmark on the flywheel is a few degrees forward of the mark on the case. Is this a problem?

next question, this is the first time with the valve cover off, how can the ex cam be one tooth off? Can they jump?

  • grayracer513

Posted December 02, 2009 - 08:19 PM

#2

  • Move the crank back to where the mark on the case aligns with the "H" on the flywheel.
  • Move the exhuast cam back from its correctly timed position
  • Move the intake cam back
  • While holding tension on the chain, slowly roll the crank forward until the "I" on the crank aligns with the mark on the case
  • Check the timing

Yes, the cams can jump time. If that's the case, replace the cam chain and chaeck for signs the cams have seized. Torque the cams caps down CAREFULLY.

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  • cbesing

Posted December 02, 2009 - 08:40 PM

#3

Do I do steps 1-3 with the the the chain loose and then add tension for step 4?

Thank you for your help!

  • grayracer513

Posted December 03, 2009 - 09:07 AM

#4

Yes. Turn the crank back, turn the exhaust cam back until it starts to move the crank, then turn the intake back until it pulls against the exhaust. Turning it forward from this point pulls the front and top runs of chain taut, as they are in operation. Without tension on the chain, the crank can be moved 10 degrees or so without moving the cams.





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