Problem with cam timing ATC90

[TheRadBaron]

This seems like something that I should be able to figure out by myself but I'm having trouble with it. I think I've been working on 2-strokes too much. Camshaft? What camshaft?
Anyway, I'm installing a new cam chain on my '77 ATC90 to replace the stretched out old one. The problem is that I can't get the circle mark on the cam gear to line up with the notch on the head when the crank is at TDC. It's 1/2 of a tooth off. In other words, when the crank is at the TDC mark, the notch is pointing at a pin on the cam chain, not between the pins where the circle mark is. Does this make any sense?

If I line the up circle with the notch, the crank is either at the "F" mark or about 1/4" after the "T" mark.
Again, this might be something totally stupid that I'm overlooking but I thought that maybe someone here could give me some insight. Anyone seen anything like this? Thanks a lot.

[effort=results]

Have it land just a lil above the notch on the head. I just did my 110 today and havin troubles. So moved it where it was just a lil after notch and it was off. So back to just a lil before the notch