Cam Timing

[Roon-E]

Hey Guys,

just finished a top end rebuild on my '94 xt600e.

One thing strange (maybe) was when trying to line up the timing marks on the cam sprocket using the TDC mark on flywheel / crankcase, it wouldn't. The marks were slightly forward of where they should be, but if I took it back a tooth the marks were slightly back from where they should be.

Unfortunately I wasn't the one to take it apart so have no idea if it was lined up slightly forward or back or spot on and I've just done something wrong. Maybe I'm just looking for a little more accuracy than's really there???

turn's over by hand well, good compression. nothing seemed wrong so I fired it up and seemed to run well, but I don't want to ride it / run it any longer untill someone tells me they had the same thing or where I F**ked up...someone...anyone??

cheers guys

[aukeboss]

This is normal, just set it so that the difference with the theoretical position, one tooth back or one tooth forward, is minimum.

Auke

[rickg]

It may be the chain has stretched a little so that the mark is behind (retarded) the place it should be? If Aukeboss says this is normal I'm sure he's right.

If you were being keen you could put a degree disk on the crankshaft, mark where TDC is and then note at what angle the valves just open and close and compare this to the cam timing in the manual.

Putting it on one tooth out from where it was will make a difference to the cam timing and engine performance.

Always do what you have done: check it turns over ok by hand before you boot it into life.

[*Touring Ted*]

Its never "Exactly" on the mark but you just have to pick the closest.

[lecap]

The marks fit when the timing chain and rails are new. The more the chain stretches the more the cam lags behind. Not sure but I think your chain is scrap (the moment when the tensioner rail does not take up the slack any more)before you are a full tooth behind. I would rather set the timing late with the camshaft lagging behind as ths is what it does as the timing chain stretches.