The engine runs fine at idle and at full speed until the engine warms up and gets hot. The engine will suddenly die on me at full speed. I immediately restart the engine and will run fine for a few minutes and do the same thing. I have had it to several boat shops in which the have changed the spark plugs and fuel line coming from the tank but this hasn't helped. Anyone have any ideas? I was thinking it could possibly be a coil but wanted to check before I go out and buy anything.