2006 crf250r cam chain and timing

[medhatrider]

Doing the top end on my 06. Figured I would check the timing first. So I lined up the punch mark with the arrow on the right side cover to get TDC, the 2 marks on the cam sprocket line up with the top of the cylinder head. But when I checked the inspection hole on the left side stator cover the line on the threads is a little passed the 2 marks on the flywheel. I have tried to get this all to line up by moving the chain back and forward a teeth on the cam sprocket. Still cant get it right. Its off only like half a tooth or less. Am I correct in thinking that the chain has probably stretched a little over time??

[bucket list]

Ya they do stretch over time. the best why to check is with a dial indicator and degree wheel on the crank. The exhaust valve should close at 15 degrees ATDC and the intake should open at 15 degrees BTDC all at .040" lift.

If there getting any way near 0 and 30 the chain is stretched a lot.

[Eddie8v]

The 2nd flywheel mark should align with the groove in the case threads.

[sjvmtb]

Are you releasing the tensioner before checking? I believe the chain needs tension on it to check the marks correctly.

[medhatrider]

Thanx for the help guys. I looked at it again and the groove aligns with the second mark. Might replace it anyways seeing how im gunna do the top end and might replace the flywheel with a heavier one. Thanx again. This is a great site!!!!

[Eddie8v]

2nd mark is perfect.