[Rich Biebel]

I could write a book on Onan random, intermittent shutdowns.

Heat is a big issue on air cooled gas burning units.

Installations in MH's and trailers often disregard the guidelines for proper cooling and isolating the cooler intake air from hot exhaust air.

Any machine install can be easily checked with a heat gun to see what the air temp is going in vs ambient air temp.

If warmer exhaust air is going in the machine it will run much hotter and can and will do serious engine damage..

Do anything you can to wall off the exhaust side hot air on the right side from being drawn in at the cool air intake. You can easily feel where that air is being drawn in under the machines left side front......

New style 5.5 and 7kw Onan generators routinely are installed in a way that the hot exhaust air can easily be drawn in on the cool air intake side.

It can cause fuel to vapor lock and the machine shuts down in extreme heat.

Contol boards and fuel pumps routinely shut down the machines in the same way and it is very difficult to diagnose since it is random.

I work on these machines all the time and since many are used commercially I routinely change both items.

Its a very common problem and unfortunately costly to repair mostly because the control boards are expensive.

I just had a machine mounted in a gooseneck trailer up front. Replaced control board and fuel pump and made some sheet metal to block hot air from being drawn in.....

This summer I have seen this problem develop in a brand new living quarters trailer. 20 hours on the machine.

Nothing stopping the hot air problem.....and the machine shut down just from the heat. A fan blowing the hot air away from the inlet side and it stayed running.

At that same event I replaced a control board and a fuel pump on a 5.5 that was shutting down after 15 minutes to a half hour of run time......