Onan 4000 shutting off after 20 min.
Have an Onan 4000 300hrs in a Class C. If I'm sitting still it will run about 20 minutes then sputters and sounds like it's running out of gas and shuts down. If I wait a while it will start back up a...
Forum Discussion
DrewE wrote:
I think by far the most common cause of this on these generators is the fuel pump dying such that it doesn't work properly when hot. You may be able to verify that by comparing the sound it makes in priming mode (holding the control switch in the off position when the generator isn't running) when it's cold vs. when it's hot and has just died. Most, but not quite all, versions of the 4KY have the prime function.
While ignition system components can also get temperature sensitive, and that's not unheard of, it's not anywhere near as common as the fuel pump, from what I've been able to suss out.
Yea I have the prime function. I ran it yesterday and it shut down 4 times. To trouble shoot the fuel pump I tried to start it as soon as it stopped and got it running right away every time but had to prime it. I ran it with no load and ran it with the AC on, same result. That leads me to believe it's not the pump because it would run with no cool down. The weird thing is after the 4th start it ran for 2 hrs until I shut it off because I had to leave. Came back and hour later started it and ran for hours until I finally shut it off. I know my way around an engine just not that familiar with all the different components of an Onan. I can't trouble shoot now if it won't shut down. Going to start it now and then to see what result I get.
