Everytime that I go out on the ocean and run my engine at full power it shuts down after about 5 minutes. I try to pull start the engine but it will not start. After a tow-in and it is out of the water on the wash rack for about 30 minutes it will start after a few pulls??? During my attempts to restart the engine, I pumped the fuel ball and there was fuel in the inline fuel filter. Was told that it was an overheat problem so I changed the thermostate but this did not help and the problem continues.