I have a 2000 Chaparral SSI216 with a Mercruiser I/O and the engine is a 5.0 liter. Recently after running the boat for about an hour, and then shutting the boat off, if I try to restart within 30 to 45 minutes, the motor tries to start the idle jumps from 500 to 2500 RPMs and then dies. At this point the boat will not start until is sits for a couple of hours and then it fires right up. We are having extreme heat, 103 range. This has happened to me twice. Now if I shut off the boat and it sits for an hour or so before trying to restart, it fires right up. I have no issues at all when the boat is running, only when trying to restart after running for a while. Is this vapor lock and if so, how can I remedy this issue?