[sluggo]

If it seems heat related and warmer raw water=shorter time before fault, assuming it is so equipped I would start by looking at the exhaust temp switch. put a meter on it when cool to figure out if the switch is normally open or normally closed. The run the generator until it shuts down and see if the switch tripped. You can do the same for coolant temperature, etc.  I would put a heavy load on the unit and see if that accelerates the shutdown sequence. The higher the load the higher the exhaust gas temperature. High egt can come from a restriction in the shower head, (diverting the spray away from the sensor), restriction in heat exchanger or oil cooler, etc.  It's also not unusual for exhaust temp sensors to go bad.

thank you for the response I will look at those again.  We have changed the exhaust temp. switch at least once, but I guess it wouldn't hurt to trouble shoot that again following what you said.  I will let you know.  Relative to the load, it does not seem to matter, I ran it Sunday with almost no load, ie A/C and the result was the same.  I'll keep trying and keep asking!! and thanks again for the response!!