Onan 2600 generator

[larrylwill]

My 08 Roadtrek has a Gen with 71 hours on it. In Dec we ran it for about 4-5 hours to keep warm coming back from Fla. Since then I have run it every month for an hour or so. Today I started it and turned on the AC and it ran about 10 minuets normally then started to surge then shut off. I found it was low on oil. So I filled it up and it again ran for about 10 minuets then surged a few times then stopped.
It will start ok but only run about 10 minuets then stop, it doesn't surge so much anymore it just stops. I tried loosing the gas cap, didn't help. I will replace the fuel filter in a day or 2 and try running some seafoam through it. Any other Ideas?

[larrylwill]

I finished replacing the Gen. I put on a new fuel pump, new filter and all new hoses and mounted them on the outside of the gen.
I ran it for over an hour not loaded, I haven't hooked up the 3 output wires yet. During the run It would occasionally sputter, The filter which is also clear is about 1/4 to 1/3 full of air. I noticed air in every line except right at the carb. I never noticed any air entering the carb but it must have been inside the stream.
Coming out of the tank is a plastic fitting with a white plastic barb about 3/8" then there is a 6 inch long black stiff piece with white C clamps on each end. You put this over the barb and slide in the wide c clamp on, you can push and pull the line and rotate it. The out end there is a right angle stainless steel double barb about 3" long. One end goes into that black thingy and the other to the gas line. Its also not tight you can move it in/out and around.
I never saw air coming out of the tank but about 1 ft from it the line goes up and a bubble would gather there and move a round, it never went away. If I lowered the line it would move away but come back as soon as I let it go. I took off the black thing and put the stainless 90 right into the plastic output from the tank and then taped it so I know it couldn't pull air. It didn't help. So I have to assume the leak is in the tank pipe. I suppose I have to call Roadtrek to get a new one. It is about 2" round with threads and screws into the tank, with a right angle barb on the output in the middle.

[My_Roadtrek]

It is possible to replace the gas filter without pulling the gen-set. I think Handbasket did it, but is was a pita.

[larrylwill]

I put a piece of clear silicon tube after the filter into the carb, and at the gas tank. After running a while 20-30 min, I saw bubbles that got worse until foam then it quit, no air at the tank output.
Next I removed the tube from the gas tank and put some gas with cleaner in a can and ran again. No bubbles from the can but again bubbles at the carb. So it appears that either there is a air leak between the input to the gen through the filter to the carb.

Unfortunately the great engineers at Onan never left enough hose to replace the filter without dropping the gen. So now I have to remove the gen to remove the green cover to replace the filter and hose.

The new setup I will run the hose from the pump which I will mount on the outside of the case and drill a hole for the hose up front and it will be a straight shot to the filter and the carb, so I will be able to see all the fuel flow except in the main gas tank. Which was clear, no bubbles. I'm guessing it was one of the fittings or hose clamps. I will connect the carb to the filter and run the hose out the side, then mount the gen then the pump then finally run the hose to the mane tank.
If they had human engineers at Onan they would have put a small cut out or door at the fuel pump and left enough slop to remove and replace the filter, but they want you to go to a dealer to get it serviced.

So ordered a new fuel pump, filter and hose. Total cost under $55
Looking at the fuel pump I pulled out, it was doomed to leak.
One end has a welded right angle connector with a hose barb adapter screwed into that.
The other end has a welded straight adapter with a right angle adapter screwed into that and a metal(rusted) tube screwed into that and then it bends 90 degrees and 4 inches to another hose barb.
I think mine was leaking air at the metal tube adapter, its discolored where it screws into the right angle adapter.
I'm going to replace both ends with just a straight through hose barb adapter, no metal tube as soon as the hose gets here. I got the filter and pump today.

[rwj146]

If it is the fuel pump then yes the generator has to come out. I had mine repaired at Cummins Southern Plains. Pricy little bugger.

[larrylwill]

Did you have to drop the gen to replace it?

[Liketoroam]

Mine reacted the same way a couple of years ago. I changed the fuel pump. It would run until it starved itself of gas. The pump wasn't strong enough to keep up with demand.

[larrylwill]

already did, see first post

[bobman]

try running it with the gas cap off the tank, maybe the vent in the cap is plugged and its pulling down to some type of vacuum and not getting fuel after the 10 minutes

just a thought

[JPeyton]

oh these things are such a joy. Guaranteed when you're out on the road and need it it won't work. Cheap plastic starter tips that break, turn it off underload and you blow some electronic component that's impossible to get to...

Anyways, I would run it without any load for 15-20 mins to see if it is a load draw causing it (sounds like it). Could be the VR but you'd probably see the fuse pop.

[larrylwill]

No just a 38 special.

[BudJ]

larrylwill wrote:
I just went out and started the gen, it ran about 5 min unloaded and I heard it puff one time then smooth out again. I then turned on the air condition and it ran until the 1/10th turned over about 15-20 min total. Then it cycled about 3 times the just stopped dead. I immediately started it again and it ran about 30 sec the just stopped dead again, then It wouldn't start. It acts like its starving for gas, but what do I know.?

Do you have a 44 Magnum?

Bud

[larrylwill]

I just went out and started the gen, it ran about 5 min unloaded and I heard it puff one time then smooth out again. I then turned on the air condition and it ran until the 1/10th turned over about 15-20 min total. Then it cycled about 3 times the just stopped dead. I immediately started it again and it ran about 30 sec the just stopped dead again, then It wouldn't start. It acts like its starving for gas, but what do I know.?

[larrylwill]

I'll be changing the filter this weekend and running something through the carb.

[loving_retireme]

I also felt it might be the VR, but why would it always stop after 10 minutes and not be random. The Onan uses about 0.4 gallons an hour (under light load) and since "larrylwill" unit is only running about 10 minutes it's only burning about 9 oz of gas before stalling. Sure sounds like it is gas related. I am with Handbasket on this one, not a gummed up carb (it runs well before quitting), but a clogged fuel filter or something else cutting off the gas supply.