Engine starting issues....

I have a 2003 Mobius LSV and am having issues with the engine starting after its has been running awhile. I thought I was draining my battery with a short of some kind but I ruled that out this weekend when I had a spare, fully charged battery to put in the system.

The boat ran fine all morning and I pulled into a cove to hang out for awhile. When I got ready to leave the boat would not start. I felt of the engine and it was very hot for sitting around not running for at least 3 hours. This morning I stopped by the marina and out of curiosity I decided to start the boat. It started right up, no problems. I thought this was a battery issue at first, then I thought it may be an issue with my alternator not charging. Then I thought it must be the starter...

I haven't noticed the temperature gauge running hot....

Any ideas on what could be causing this? It appears the engine is refusing to start after it has heated up...

Sounds like you could have the vapor lock issue.

Can you explain more?

Due to a poor design, the fuel pump is located in the engine compartment. This makes it convenient to get to for service. However, it also means that the heat from the engine will "soak" into the pump. When running, fuel flows from the tank and cools the pump. When you stop, the heat from the engine heats the fuel at the pump and can heat it from a liquid to a gas. This gives you a vapor and that prevents the engine from running.
Next time, try pouring some cool water onto the pump. My boat will start up no problems after that.