i just rebuilt my engine and im putting the timming belt back on and the timming marks wont line up. i have the cams in the correct position and i line up the crank whit the mark and put the belt on and rotate it a few times and the cams still line up but the crank wont it looks like it is a tooth off or something. the belt is always too loose between the crank and exh-cam.

can any one help me