[Joeboch348]

This has happened 2 days in a row. Running my 93 3100 about 5 miles up the coast to my fishing spot. After fishing for a couple hrs I head back running between 24&32 rpm just as I get to the inlet the port engine dies.  It turns over but seems like no spark. Then 15 mins later at the dock it fires right up. Any ideas?  It runs cool 150degrees

[HIGH SPIRTED]

Heat maybe the problem with the distributor cap and rotor with spark leakage. Look at the engine in the dark when it is up to temp and look for sparks around the distributor and the spark plug wires. that is a cheap fix

[RMS]

Joe, What model engines do you have? Are they fuel injected or equipped with carburetors? When the engines are off and you turn the ignition key to 'run' are there any beeps from the dashboard? Bob

[Sans Peur]

Lots of paths to follow but I would look at the coil first. Sometimes they will heat up and stop working. Soon as they cool down they start working again.
Second avenue would be the ECM. However, before you start throwing money and parts at it I would have a professional look at it.