too much fuel...I think...

So we were out on the lake this morning on the boat starts perfect and runs perfect for about the first hour. Then it starts being difficult from whole shot...most of the time it will die if you just throttle it too much. But if you can ease into it, it will run perfect. Idle is fine. The initial first cruiser gear is fine. But when you try to get on it, it doesn't go. There was some fuel smell associated with it so it seems like it is getting too much fuel possibly. And the symptoms seem like almost a flooding issue. I am not very mechanical, but what are some steps I can take to troubleshoot? Any help would be greatly appreciated.

FYI, we had this problem last week and assumed it was a plug. Found one that had a fair bit of carbon build up on it, so we cleaned it up. After that we fired up at home and was seemingly running well.


info: 2003 Supra Launch SSV, Indmar Assault MPI 320 5.7