FR3 Onan Generator - won't keep running

[kk6t]

Just got back from our first long trip in our 2015 FR3 (5 weeks). The weather was very warm. We wanted to use the generator while on the road so we could use our roof A/C. Generator won't keep running. It starts fine and then runs anywhere from 15 minutes to 2 hours and stops. The fuel level was always 1/2 tank or more so that wasn't it. The oil level was fine. Someone told me the generator was probably overheating and shutting down. The problem I have with that is that it happened while we were driving at highway speeds.

Any ideas?

[HONDAMAN174]

Check your oil level. May need to be at its highest point.

[oldgold]

Have you changed the oil in the Onan yet? Mine started to crap out like that at 17 hours. They told me to keep the door open and run it to 20 hours and then change the oil. It also could be fuel sloshing around while on the road and the fuel hose not picking up. Not sure how the FR3's tanks are setup. In our toy hauler it will only let you pull to about a third of the tank. The theory I guess they had was they didn't want the generator to cause you to run out of fuel.

Overheating could very well be the culprit though. Is there a vent sound your generator anywhere that could be opened?

[waiter21]

Mine does similar when the tank starts getting down about 1/2.

If I'm parked, it'll run down to about 1/3 tank of gas. but when traveling, it seems like 1/2 tank is about the lower limit.

HondaMan also mentioned oil level, this could also slosh around while traveling, make sure its full.

I'm going to add a air vent to my compartment door to help with air flow. The chassis engine puts out a lot of heat. That could aggravate the problem.

[j free]

could it be vapor lock from over heating?

[ChrisAndGarren]

We had a similar problem in our Georgetown - i had Cummins spend a week trying to replicate the issue and no dice.....so, I had them change the oil, fuel and air filters and the oil itself. Has worked like a charm ever since.

Speculation was it was the carburetor or the fuel filter on ours - may want to change those filters with the oil and since if it works any better.

Good luck!
Garren

[RubberNail]

Keep in mind that you are fueling with ethanol gas, unless you've opted to pay another 25% for non-ethanol gas. Means you need to be religious about running for an hour each month, whether or not you are using the camper. Also, good to use a marine grade fuel stabilizer with each tankful. I have a 4.0 Onan in a class "C", a Onan 5.5 in a 5th wheel, and 2 mixed brand 7.5kw generators for use on my farm. Had trouble with the 4.0 until I realized that all the others were running with non-ethanol/stabilized gas. Took several hours restarts and running the 4.0 with stabilizer before it would run smoothly, without occasional dying. No sure that has any relation to your problem, but food for thought. Ethanol gas is a killer for any engine that not run long and often.

[RamblerGuy]

Do you have a water heater with an electric element? Of so, maybe it was on and when the thermostat called for heat the load added to the A/C and other loads became too much, causing the generator to stall. I've had mine stall before the circuit breaker could open.

[Brewster McFrisk]

Had the exact same problem with our FR3, new fuel pump new filter, everything you could think of. Then I insulated and foil wrapped the fuel line going to the generator and haven't had a problem since.

[Bobbug]

The onan generators (especially in hot weather) can get vapor lock which will cause the problems you describe. Its an easy fix: disconnect the fuel line from the carburetor and thread a "pipe insulation" material over the fuel line between the carburetor and the fuel pump. Re-attach the fuel line. The problems will be solved.