not getting fuel to carb on Onan generator

I have the same generator.

Have you checked the fuel pump fuse located on the lower RH corner of the Generator Set Control Panel?

If you have and the fuse and connection is good you can test the pump by doing the following.

1. Disconnect the rubber line that runs from your fuel pump to your gas tank.

2. Disconnect the fuel line where it enters your carburetor and point it into an empty container to catch any discharge during subsequent testing.

3. Connect a temporary line from the fuel pump inlet into a full gas can

4. Press the start button on the side of your generator. The electric fuel pump should immediately turn on and start pumping gas from the full gas can into the empty container.

Steve

Don't squirt starter fluid in a gas engine. You can blow the heads clear off the engine.

This may be a stupid question but, will the generator run with the engine running. There should be and evidently there is a in-tank pump, from there it goes to a pressure/flow regulator. From the P/F regulator it goes to the engine and the generator. It does not take much of a blockage any where on the line to stop the generator pump from sucking fuel out of the tank without an assist from the in-tank pump.

I would check first at the place where the fuel line "T"s off to the generator and work back to the generator pump.

It may seem silly but you're just grasping at straws right now.

If no fuel is coming through the line when it's disconnected from the genset, then either you are out of fuel, the pickup line in the tank is sucking air due to deterioration or misplacement in the tank, the line itself from the tank to the fuel pump is deteriorated and is picking up air, your fuel pump has failed, your fuel filter or the fuel line is stopped up or you have a blown fuse or disconnected wire to the fuel pump. Those are really the only possibilities for the given circumstances you describe. I'd start by eliminating the simplest one and make sure I didn't have a blown fuse. Then check the filter, then the lines between the genset and the pump, then the pump and then the pickup line inside the tank.

Let us know what you find.

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

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

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.

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.

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.

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