Last weekend we went to pull someone out of the water and when the boat was put in gear the RPM's shot through the roof but nothing happened. Sounded like the engine was fine, just the transmission was not spinning. It could limp back in reverse (barely). We figured it was the damper plate but after taking it into the shop, they say that the damper plate looks fine. Fluids are fine. It's a PCM GT-40 engine in an '97 MB Sports Boss 200ls. Any ideas what the issue could be?