[Rich Biebel]

All Onan’s are designed to run with the service door in place.
The air flow is dependent on the door being on and tight
They do not have a high temp shutdown but will shutoff and it is from the control board and or the fuel lines, carb etc getting to hot
Many installs of these units ignore the airflow issues that make running hot worse
A fan directed at the compartment and to blow the hot exhaust away from the cool air intake area usually will help
The cooler air is drawn in along the bottom front area behind the oil filter and to the left.
With it running there is a very strong suction there and can pull a rag right out of your hand
I’ve seen birds nests up in there and bags or debris.
The lower they are to the ground the worse it can be
These units rely on air to cool and heat routinely causes cylinder head failures
The guides loosen up, valves and springs suffer from the overheating and the oil turns to sludge around the spring bases.
I do head replacements all the time. Finished one yesterday. Third one I’ve done in a month.
Anything you do to reduce the heat being drawn into the machine is a big plus.
I’ve seen one machine on a sign truck from Miami area with head failure from running to hot and it had under 1000hrs
Was mounted on the side of the truck very low to the ground and obviously was run in a hot area….Miami !
I work on them all the time.

My own 4000 watt Onan’s also would shut down if they got hot.
A big pit fan blowing directly at my trailer compartment mounted unit stopped the hot shutdowns
Do not run Onan’s with the service doors off ! Like I said it disrupts the designed air flow and will shorten the life of your machine. That goes for any Onan