I actually just had this problem and had to have my hub replaced. On mine I was idling out past the no wake bouy and took off to get on plane and about 2 minutes into the ride the boat just stopped moving and the motor stayed at a high rpm. I slowed back down to an idle and after a few minutes tried to take off and get on plane and as I gave it more gas the rpms continued to increase but the boat didn't move. We had to pretty much idle at 5mph the whole fishing trip. Hope this helps with any questions you had.