My 1995 Monte Carlo is running great but going nowhere. I believe it is the engine coupler.

I have a couple of questions. How can I diagnose this to make sure where the problem is? I have the plastic guard off and the rear coupler to the jet housing seems solid. Everything is turning but I think the coupler toward the crankshaft is stripped. Everything spins, but the ski doesn't move in the water. Nothing is obstructed, the impeller spins freely.

Secondly, is the coupler threaded?

Third, what is the best method to get at this part? Pull the engine or take apart the jet housing?