Generator Issue

[Planeteer]

Uncovered the motorhome this evening to get ready for a Florida trip in 2 weeks. Started it up to drive the kids up and down the driveway, but quickly realized fuel was pouring out of the generator. Got kids out quick but they were not happy LOL. Didn't want to explain to a 1 and 3 year old that we could blow up.

So, it's cold out and I don't have a chance to troubleshoot right now. But it seems when the (chassis) engine starts, fuel starts pouring out of the air intake on the generator (Generac Primepact 55g). Motorhome is a 2000 Chevy 3500, Gulf Stream. Any ideas to save me troubleshooting time? I still have to install the new water heater and some other smaller projects, but my 2 week window is feeling shorter and shorter...and plenty of rain in the forecast 😞

[Planeteer]

This is related to the fuel issue:

I went to W***mart last night and got a new fire extinguisher. Got home, and the pin was pull and gauge said Empty. I knew I should have opened the box first.
That was my 2nd time in that store in a year...that's why LOL (last visit was just an eye doctor appointment)

[Dusty_R]

If the generator has an electric fuel pump, just unplug the wire at the pump.
I added a switch to the fuel pump on the generator, and turn it off while the generator is running, and let the generator run out of gas when I know that I'm not going to use it again for a while.

[Cobra21]

A cheap fix that "can" work. Pour one or two cans of Seafoam in your gas tank depending on how much gas your tank holds and run your genny on this. Since it started to run properly, this will most likely take care of it.
Brian

[theoldwizard1]

Byork wrote:
I'm assuming it was the needle / float, so I still have intentions of installing the fuel shut off and cleaning the carb.

The fuel shut of is a good idea. The carb is not broke so don't fix it !

From what little research I did on that generator the fuel pump is part of the generator itself. It may be electric, it maybe be vacuum.

[Planeteer]

Update: I went out to work on motorhome with a step by step plan to troubleshoot the generator. Then my curiosity peaked and I tried to start the generator. It started and ran fine. So I started the chassis engine again....no fuel coming out anywhere 🙂

I'm assuming it was the needle / float, so I still have intentions of installing the fuel shut off and cleaning the carb. I bought a fuel shut off but it is cheap and plastic, so I made a nice metal one with a ball valve and barbed fittings.

Thanks again for the help guys. For now I'm going to continue on with my pre-trip projects, then head South in a couple weeks!!

[Planeteer]

Thanks guys, good ideas. I'll try opening the gas cap to relieve any pressure, when I run home today at lunch. After this happened I hit the primer button on the gen just to see if it worked. It sounded like it was priming normal, and shut off when I let off the button.

I am thinking after work I will pick up a fuel petcock to install on the line just before the gen and shut off the fuel. My main goal right now is getting the rig running (without fuel pouring out), replace water heater, then solve this gen issue properly.
I'll probably try cleaning the carb first, as a new one looks pretty pricey.

Question is...If I shut off fuel supply to gen, could I travel that way if needed? Hopefully the pressure isn't going to force fuel out of somewhere else

I really hope the tank isn't getting pressurized by a fuel pump issue, that's a project I don't really want to tackle right now LOL.

[MitchF150]

try taking the gas cap off the main gas fill and start it up.. See if fuel still comes out of the gen..

Sounds like the tank is not venting?

No idea really, but something is pushing fuel to the gen when it does not need it..

Good luck!

[garym114]

Don't know where the fuel pressure to the gen is coming from, that shouldn't be happening, but fuel coming out of the carb at the air intake indicates the needle in the bowl of the carb is stuck open.
Open the fuel cap to vent off any pressure in the tank. Only two things will run the fuel pump on the gen, the gen is running or the fuel prime is on. Neither has anything to do with the chassis engine running.

Stuck needle valve is probably caused by gas sitting in the gen carb for a long time, evaporating, and gumming things up.. It is difficult to actually see the needle with the bowl on the carb removed. With the bowl removed the needle should move up and down with the float. A little carb cleaner sprayed at the needle bottom should free it up.
Don't try to take the float out unless you remove the carb.

Yours is very similar to my Q-55G

[theoldwizard1]

I re-read the original post. Seeing as you are short on time and the weather is not in your favor, find the owner's manual for the generator. It should list the part number for the carburetor. Just buy a new online online. Don't forget to check Amazon !

[theoldwizard1]

First, have a fire extinguisher handy and pull the spark plugs on the generator and turn it over by hand if possible. You likely have gasoline in the cylinders. Also it is likely have gasoline in the oil sump of the generator.

Likely there is a small electric fuel pump that sends fuel to the generator. (I thought these fuel pumps only ran when the generator was on, but I could be wrong.) The needle and float in the generator carburetor are not sealing closed. It could be a bit of dirt holding the needle open or you might need a new needle. Either way the carburetor bowl needs to be dropped. Sometime spraying the needle with some carburetor cleaner will clear the dirt.

If fuel is still pumping out of the generator after that attempt, the carburetor will have to be rebuilt with a new needle. Make sure to check that the float is not leaking/sinking.