not getting fuel to carb on Onan generator

[mcal63775]

Onan Marquis 7000 it started rough but it cleared itself out after a minute or so. Ran smooth for 10 minutes under a light load powering a small space heater and running microwave and all the interior lights on. Then it started to bog down for 3 seconds, recover , run 30 sec. bog down again, run 30 sec. bog down and eventually died. Have not been able to get it to run since. I pulled off fuel line to filter and no gas came out of filter or the fuel line. I used starting fluid to get gen to run, squirting enough to keep gen running, expecting fuel to come out of fuel line. No fuel. Is there an external fuel pump for my generator? or is it an electronic pump? Generator gets its fuel from main tank of MH.

[cbr46]

I have an Onan Marquis 4000 on an 02 Fleetwood . . . .

There's a filter on the bottom of the gen housing and a 2nd filter at the carb inlet. NAPA makes a 100% match for these.

It's a long shot but blow into the fuel line and listen for bubbles in the tank (remove fuel filler cap?). I WOULDN'T use a compressor! If there is a clog that might free it up. If there's total resistance might be a total clog. If there is hissing that would be your air leak but you'd need a very quiet environment and a helper with good ears to hear it.

You can also try a big syringe. If you get air and no vacuum 'pop' when you remove the syringe then you know. You could use the syringe to pressurize the line also. I don't know how many psi a syringe typically generates as fuel sitting in the line would affect max pressure.

I would drop the tank when all else fails. That would be a big job to tackle.

Best,
- bob

[falconbrother]

Some people have cut through the floor to get to the fuel pump. Apparently it's possible on some and not on others.

[mcal63775]

After reading other forums with the same issue I have, I replaced the following with OEM parts. Fuel pump, fuel filter, air filter. I checked the safety fuel valve solenoid and it works. Got it all back together, and yet again, no fuel. Having the fuel line disconnected from filter, I expected fuel to squirt out while cranking, but nothing. When weather allows me, I will check the voltage and run a fuel line from gas can to the inlet side on pump and see what that does. I hope I don't have to drop the fuel tank and replace the line to the pump. I will update when I get it done.

[turbojimmy]

rv37tonk wrote:
1.)did you remove the fuel line to the filter
2.) place the fuel line in a bucket
3.) push the prime switch to check for fuel flow ?
note: the bottom side of the start switch is the prime switch.

Mine just has a line from the tank to the bottom of the pump. The filter is inside the pump housing. I got a couple-foot long piece of rubber hose, disconnected the feed at the pump and dipped it in a fuel can. I then hit START on the generator. It fired up immediately. This method will test whether the problem is the line from the tank. If the generator still doesn't run, then it could be the filter, the pump itself or something beyond the pump. My electric pump is loud (clicks) and is much louder when there's no fuel. I know when it's running out of gas because it starts to make an awful racket.

[rv37tonk]

1.)did you remove the fuel line to the filter
2.) place the fuel line in a bucket
3.) push the prime switch to check for fuel flow ?
note: the bottom side of the start switch is the prime switch.

[mcal63775]

jwmII wrote:
The year and model of your generator would go a long way toward people being able to help you.

Onan Marquis 7000 sitting in a 97 Coachmen with a 460 / F-53. Model # is - 7NHMFA26106F

[crasster]

Tap on the little fuel pump and/or remove it and try to clean it out. Use marvel mystery oil while cleaing it. May be simple. Check the voltage going to the pump as well.

[jwmII]

The year and model of your generator would go a long way toward people being able to help you.

[mcal63775]

I found the electric pump...right by the starter that I took out last fall,and cussed so much to get to. I had to drop my fuel tank several years ago to replace fuel pump. Can't cut hole in floor, due to my fresh water tank sits over where fuel tank is. Ugghh. I am not looking forward to this chore. If I got to tear into it that deep, new lines and a pump will be done. ANY volunteers?

[turbojimmy]

On mine, the proof was when I disconnected the feed from the tank and hooked a fuel line directly to the pump inlet, and dipped it in a 2.5 gallon gas can. The generator fired right up. After some period of denial and trying other things I came to the realization that it was the rubber line.

On mine - and yours may be totally different - there is steel line that runs from the generator to some random point under the chassis where it turns to rubber. The rubber line then connects to the pickup at the top of the tank. That rubber line was shot. I couldn't get my tank out so I had to cut a hole in the floor to get at it. It wasn't pretty, but it was an opportunity to install tile in place of the hideous carpet in that area.

[mcal63775]

97 Coachmen F-53. Well crap. I guess its going to be a fuel line or the pump. Oh how fun this ought to be.

[turbojimmy]

What year MOHO? On my '84, the rubber lines had deteriorated and were sucking air rather than fuel. I had to replace the line from the genny to the tank. You might also want to check the fuel filter and make sure the fuel pump is running.

[mcal63775]

Got plenty of fuel in tank. I have not read where someone else had the same problem. I guess I better chase down fuel line from filter and see where it leads me to. Probably to a pump that I can't get to. I wonder Is there a fuse to check for the pump.

[midnightsadie]

if this is on a MH?? most have a safty shut down IF the fuel tank is at a quarter of a tank.

[turbojimmy]

My 6.5 has an electric fuel pump too. It will run out of gas if the MH tank is below 1/4.