Okay so here is the problem. The Engine starts and runs great, can even get up on plane with no problems. I run it a good 15 min and then suddenly it starts to sputter and shake a bit, will only go at slow speed then if I slip it in neutral or turn it off and wait a min or two it will start going again run fantastic for another few min then sputter and shake again. I was able to get it back on the trailer, while it was running fine. I am not sure where to begin?