Took the head off, slipped the timing belt off, put a head back on, the timing belt gave some slack. Put the timing belt back on, the cams are in, the timing is correct, but the timing belt has a bunch of slack, please tell me there is a way to tighten it without pulling the pulleys off. I tried turning the motor backwards because I heard this gives the auto tensioner tension, but instead it made the belt skip a tooth. Please help, I have to have this done.

Thanks