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sconym's avatar
sconym
Explorer
Sep 03, 2013

Onan 5500 Marquis Gold - Stops running

Thanks in advance for all the advice. I have an Onan 5500 Marquis Gold model number 5.5HGJAB-5900D Spec D in my toy hauler. I am pretty religious about running the generator once a month or so. I went out today to do my seasonal maintenance before camping season starts (oil, oil filter, spark plugs, and air filter). Before I started maintenance, I wanted to warm the generator up. It started up, but seemed to take longer than normal to start. I left it running and after a few minutes, the generator started to idle rough and then shut down. Almost seems like it ran out of gas. I went over to try and restart it and it would crank, but would not start. I let the RV sit for about 30 minutes while i was finishing some other work, and the generator started right back up. However, just like before... it surged and shut down after about 10 minutes of use. I did a search of the forum, but couldnt find any issues like this. I havent done the maintenance on it yet btw...

Thanks!

6 Replies

  • sconym's avatar
    sconym
    Explorer
    Sep 08, 2013
    UPDATE... I resolved my generator issue! It turns out that the fuel pump was the culprit. I did some more research on the net and read a few posts from people with the same issue. It seems that they were all having the same problem with their generators at approximately 450-470 hours. Mine has 471! I ended up replacing the fuel pump with a direct fit Airtex unit that was only $50. I did have to swap the electrical connectors however as they are backwards. Other than that, it was a simple 15 minute fix. Ran the generator for over an hour yesterday at full load with no issues! Thanks again for all the assistance!
  • becworth's avatar
    becworth
    Explorer
    Sep 03, 2013
    We are having a very similar problem right now. The difference is that the generator will start fine, will run under load for approx 20-30 minutes and then quit. If I turn off the generator breakers so there is no load, it does not quit. Just had the fuel, oil and air filters and oil changed on the unit. Any suggestions would be greatly appreciated, we're trying to use it this weekend.
    Info on unit: Onan 5500 Gold, Serial #L060998054, Model #5-5HGJAB-1038D Spec D, 50 amp
  • Clay_L's avatar
    Clay_L
    Explorer
    Sep 03, 2013
    That can happen if it sucks air. Mine was due to a loose clamp where the rubber fuel line transitioned to the metal line near the gas tank. You might want to check for loose clamps or cracks in the fuel line.

    To eliminate the fuel pump you can run a hose from the filter on the back of the fuel pump to a can of gas and see if it runs okay.
    It is a good idea to have the gas can about as high as the filter because the manual says the pump doesn't have much lift capability.
  • yankeeflyer's avatar
    yankeeflyer
    Explorer
    Sep 03, 2013
    Take the air filter off and spray the carb with carb cleaner while cranking it,worked for me like a charm.Carb must have been gummed up.Also make sure you have more than 1/4 tank of gas in vehicle.
  • WyoTraveler's avatar
    WyoTraveler
    Explorer
    Sep 03, 2013
    Does it throw any codes? Several on here had problems with generator in hot summer months throwing code 36. In July they replaced my fuel pump on warranty. Pump would quit when it got hot. Run after it cooled down.

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