I recently bought a 2003 Sea Doo Islandia, Mercruiser V6 250hp. When I was buying the boat, it started up just fine and the engine sounded good. I put the boat in the water, put it in drive and gave it throttle, it was going like 5mph but the engine was at 5,000rpms. I initially thought it might be the basket, but it wasn't, the basket goes up and down just fine. Anyone have any ideas???