Joe:

If it is a direct drive model like mine it could be one of a few things.

Question: Do you feel the detent when you put the transmission in forward?

If not, the cable to transmission shifter arm may need to be adjusted. Disconnect the cable from the arm and check to see if you can engaged manually. If so adjust cable.

If you feel the detent but, the drive shaft doesn't turn, you may have to adjust pressure plates on the the forward clutch assembly.

This adjustment is very easy, however, I would recommend that you invest $50.00 in the Moyer Marine Atomic 4 Manual. It is by far the best $50.00 you'll ever spend! Don Moyer explains very clearly how to adjust the transmission. I think you can order the manual on-line now at www.moyermarine.com.

Good Luck!
Steve Kaminsky