First of all I would like to thank all of the posters for the vast knowledge that is on this site. I have been reading posts for hours each day and I am learning all the important stuff to do with a four stroke. I decided to check the valve specs and one thing when I was setting the piston to top dead center according to the reference marks (9:00 oclock and 3:00 oclock marks along with the flywheel mark through the site hole) and when counting the pins between the two twelve oclock marks there is 13 pins not twelve? I counted them numerous times and still come up with 13, how is this possible?? All the valves were in spec except one intake valve which I will shim in the morning after I get some shims from the local shop. But back to the cam chain is there a problem?