Generator Questions

I have an issue with my generator shutting down while in operation in tow.

Scenario: I have a Onan 5500 genset and while in tow it has shut down about 2 1/2 hours into a trip, I an big on maintainence and checking things like oil level, air filter condition and spark arrestor cleanout. The only thing I can think of is this has happened now while in tow and the fuel tank (gasoline) was not at 1/2 or above. Was wondering if that is my issue? The genset is not flashing any codes, so I just can't imagine it is much else. It is brand new, has about 180 hours on it now, we had to run the poor thing to death during the big Derachio in June/July and it performed flawlessly then.

Thanks for looking.

Moved the post to the Generators area.

Try this the next time you are running the Genset, stationary or moving. After an hour or so loosen the fuel cap.
Do you hear the tank "pop" or a rush of air going past the cap into the tank?

If so it is possible your cap is bad and not allowing air into the tank as fuel is being drawn.

Thanks for the advice, will give this a try!