Generator Dies after 10-15 minutes after start up

[CaptainD]

Hello, I have a Onan Marquis 6500 LP that stalls out after running for 10-15 minutes. When it dies the engine studders and sound like it starving for fuel. Propane tank is full. Not for sure where to start looking. The 10- 15 minute run time makes me think the issues has something to do with temperature. Any suggestions?

[tim myers]

I had an Onan 4KW, Gas that would do that when it got hot. The fuel was vaporizing, but that shouldn't happen with a propane unit

[powercat_ras]

Next time it stalls out you can see what the fault code is. The instructions on how to read the fault code will be in your owners manual. Then you can add to this thread with the code and get more help.

On the Onan 4000, you press and release the start button on the generator itself, and a lamp in the start button does a 2 digit flash code that tells you the reason for the last generator shutdown.

On my Onan 4000, which is air cooled, if the temperature of the inlet air was very hot the generator would do a high temperature shutdown after operating 15-30 minutes, and it displayed the fault code for that. It turned on that the way that Winnebago installed it allowed the hot exhaust air to be drawn back into the inlet, making the air being drawn in on hot days well over 110 F. I fabricated an extension on the hot air exhaust so the hot exhaust air did not circle back to the air inlet, solving the problem.

[Jmcamarillo]

Have you pulled the spark plug to check for fouling? Sometimes the buildup on the plug will fall off over time or at startup due to vibration, but will foul up after running for a bit.

[reckless37]

I’d change the air filter (not really likely, but a good idea) and if that doesn’t fix it, the fuel pump.

[Tanchar]

We had the exact same problem and it turned out to be a faulty fuel pump that had to be replaced, even though it was a brand new generator ..had to take it to an onan dealer, where it was covered by warranty

[wahoonc]

Originally Posted by reckless37

I’d change the air filter (not really likely, but a good idea) and if that doesn’t fix it, the fuel pump.

Originally Posted by Tanchar

We had the exact same problem and it turned out to be a faulty fuel pump that had to be replaced, even though it was a brand new generator ..had to take it to an onan dealer, where it was covered by warranty

Does and LP fired generator even have a fuel pump?

Aaron