Generator not running correctly on full load

[J-Rooster]

There was a bad windstorm and power outage here in the Pacific Northwest yesterday. I fired up the genset and under a full load the genset sounding as if it was out of timing or sputtering? So I turned the furnace off and plugged in a small portable heater with the microwave on TV on lights on etc. and the genset ran like a top for 8 hours (until morning). I own a 04 Winnebago with heat pump/furnace. Has anyone ever troubled this problem? Thanks, Rooster

[Jim]

Most would recommend running that stuff called Seafoam through the genset. Remove the fuel hose and plunk it into a gallon of fuel with the Seafoam and run that. I had a propane Genset so never needed to clean the carb. Never gets dirty. So I don't know all the details.

BTW, I think you're suppose to run your Genset for one hour per week with a heavy load. That would mean you should have 624 hours on it. So, get crackin'. They're capable of 10,000 hours before major overhaul so try running yours more often. JMO.

[booty51]

Will the Marvel Mystery Oil keep the fuel from going bad like a fuel stabilizer? I know this stuff has been around forever. I know it is a upper cylinder lubricate. Haven't read the back of a bottle in years.I looked up Marvel on line and refreshed my remembers about Marvel. May buy some and use it.

[ksg5000]

Furnace runs on DC/batteries - portable heater runs off of AC/Generator. Think you just upped the load rather than reduced it. At any rate sounds like you might have had fouled spark plug or gunk in carb which cleared itself.

[crasster]

If it was mine, I would start by checking the plug and putting the suggest amount of marvel mystery oil into the fuel. It will clean the carb and the upper cylinder system of the engine. If it was dirty, you could get a bit more HP out of the engine thus more strength on the alternator during a full load.

[rgatijnet1]

It could also be a deteriorating rubber fuel line from your gas tank to the generator. These fuel lines eventually will harden and crack which can leak air in to the fuel and cause the generator to run erratically.

[J-Rooster]

GPWayne wrote:
I would check the fuel filter and fuel pump, clean the carb and install new plugs. Did you check it under full load after running for 8 hours? (You may have gotten lucky and cleared the crud out.) Sounds like a fuel problem. I take it is a gas genny. Your situation says a lot for running the genny under load each month. No surprises when you need it.

Wayne, I think your spot on! My wife got up in the middle of the night, which I didn't know and shut off the portable heater and turned the furnace back on full load and the Genset ran fine for the next 4 hours. I forgot to mention due to the illness of my wife's Mom we didn't take the coach out for nearly a year! That in combination with I hardly ever run my genset it's 12 years old and only has around 40-50 hours on it! I have a hunch that the gas varnished up a little which was causing the fuel (gas) not to flow correctly to the carb. I agree with your logic about it being a fuel problem. Thanks Rooster

[GrampaR123]

How many hours on your generator?

[J-Rooster]

Ray, it's a ONAN 5.5 Genny made by Cummins. My coach is a top of the line gas Winnebago that I bought new in 2004.

[GPWayne]

I would check the fuel filter and fuel pump, clean the carb and install new plugs. Did you check it under full load after running for 8 hours? (You may have gotten lucky and cleared the crud out.) Sounds like a fuel problem. I take it is a gas genny. Your situation says a lot for running the genny under load each month. No surprises when you need it.

[Crazy_Ray]

Could you PLEASE tell up what KIND of genny you are talking about Rooster????