I tried to run my fridge during the blackout and the generator in my hauler wouldn't run properly, sounds like someone is rolling the throttle on and off. I poked around some RV sites and a lot of people are saying it's bad/old fuel, which could be the case because I fell off my maintenance schedule a bit. I dumped a few gallons of fresh fuel and half a can of Sea Foam in it and let it go for about an hour with no change.

Anyone have experience with Sea Foam and how long it should take to start working?

Same thing happened to me...
I just threw parts at it.. After cleaning the carb, replacing the filter's, and fuel pump.... she worked again!

Carb is gummed up. Same thing happened to me a few months back.
I tried a few different magic elixers and ran it for hours, nothing worked.
Ended up buying a new carb off ebay for $55.

the jet in the carb is plugged. Clean it.

Carb. You need to run it every month or so with a load. Just my experience.

Not to hi-jack , maybe it will help you..

I was going to drop the genny but couldn't figure out exactly how it did..
Owners manual shows that it tilts after undoing a few bolts but mine doesn't do that..
Looks like 6 bolts on the sides and it just drops out... is that right?
It was a PITFA!! taking the carb off while the genny was still mounted.

carb, run that bad boy once a month and if its gonna sit put the stabil

I know the once a month run trick, just got lazy and now I'm paying for it. I picked up some Sta-bil and Sea Foam, was hoping the Sea Foam would clean it up without having to remove the carb...my father in law used to use it on his motorcycle after it sat and he said it worked great for him.

Legit, I haven't checked the manual for mine, but it appears to be only bolted to the floor of the compartment. Mine won't drop out the bottom because the dump pipe is directly underneath. I also looked pretty hard at getting the carb off while it's mounted and I dont think I can do it.

I got lazy as well and had exact same problem. Take the carb off and apart and clean everything. It is actually a very simple carb to work on. I used brake cleaner, don't be afraid to use a couple cans. Opposite the air filter end is some very small holes in the throat of the carb, blast those real good. Use the little tube that comes with the brake cleaner as that is good way to force cleaner through those little holes. Take the bleeder valve on the bottom of the bowl apart and make sure the little holes are all clean and not gummed up.

be careful not to tear the gaskets when taking apart, I have been able to re-use them or easy to duplicate with some bulk gasket material. Be careful as well with the needle and seat and float, don't want to bend the arm of the float.

should all be good when done

Here's the seafoam trick...
Detach the fuel line from where it feeds the fuel pump..
Stick the end of it in a seafoam can..
Start the genny.. It will be running on gas at first.. When it starts wanting to die and cough, try and keep it running by messing with the choke ( while the carb's filling with seafoam), then let it die on it's own.. By this time thick white smoke should be pouring out of the exhaust..
Now let it sit... I say at least 24 hours...
Attach the fuel line and restart the effer... it will be hard untill fresh gas get's in the line and it will look like your house is on fire from your neighbors yard, but that's what it does..
Let it run with a load untill the smoke clears could take 20+ minutes..
That will clean the entire intake system.
May not clear the carb though...

I just added the Sea Foam to the fuel tank... I'll give this a try and see what happens, thanks.

Not a bad idea to change the plug(s) out after doing this. Been doing it for years on small engine stuff.

Does it have a altitude adjustment on the float bowl? Drain the bowl, small phillps screw. Take the black plastic thingy off the altitude adjustment. Turn the needle all the way in, keep count of the number of turns. Turn the needle all the way out. Spray carb cleaner into needle seat in bowl. Put needle back in to same number of turns out.

Another thing that plugs is the solinoid in the bottom of the float bowl. Just take the wires loose, unscrew the solenoid. Spray plunger with brake cleaner. Us a screw driver to make sure it moves freely, it has about 1/4 inch movement, maybe less.

That worked for me about a month ago, Thanks for the tip over the phone steinberg55!!!

I clean carbs on the Onans constantly and I just have a bottle I pour the Seafoam into and hook it to the carb fuel line directly and squeez the bottle while letting some come out of the drain on the carb. I also sometimes start the gen with carb cleaner while it sucks the seafoam in. Seafoam also has a new Spray can too. I let it sit overnite and fire them up with carb cleaner or brake clean.

I told everyone to start the onan every month or you will be buying a Carb, I let mine sit for 2 months and it was surging, well $280.00 at the Cummins dealer for a new carb fixed the trick, Damn I feel broke.

Between the Ford 6.0 and the Onan Genny, I feel like I cant win.

Well, Legits Sea-Foam trick didn't work, it's still surging. Going to try Steinberg55's suggestion and see what happens...after that it's going to the shop. Thanks for the help everyone!

Diablo, you did not follow the directions from previous posts from honexduner! Adding Seafoam to that gas tank alone will not work at all since your carb is gummed up Re-read what the previous posts said with sea foam and I am certain it will work. If it dont work the first time, hit it again exactly the same way and it should work. Thats what happened with mine and it worked like a charm!

steinberg55 has nailed it. especially the solenoid in the float bowl. in most cases this is were the surging stems from. and it is easy to clean with the carb still on the genny. cleaning the bowl area and needle and seat is easy, just be careful not to bend or loose any pieces. inspect the rubber tip on the needle and clean it completely. that and making sure the solenoid is working freely will cure your surging problem, almost guaranteed. when you do re-start the genny, make sure you have a load on it. and not just the lights. turn on the micro or something with a decent load. a toaster will put a big load if you have one in your RV.

Mine was the Carb.

Now does anyone know the part #s and where to get just the gaskets for the 4000 carb???

I bought a pair of gaskets (airbox and manifold) for the carb on an Onan 5500 from Quality RV in El Cajon. They were only $3.10 for the pair. If you're not in the San Diego area, I'm sure they could mail them to you.