genset carburetor problem?

[chin_k]

Have not been diligent about exercise the genset, but got some time this morning. Was able to start the genset and it ran for a few minutes, then it shut down. I tried to crank it up again, but after half a dozen attempts of failure, I decided to come here and see if I can anything else.

When the starter is cranking, there is a knocking noise that I did not notice. At this point, I suspect that it is the carburetor that needs to be replaced. I know it is getting fuel, so what else should I be trying?

BTW, how long can I crank the genset? I usually hook it up to shore power when I start the genset to make sure the battery have enough juice.

[SMan]

Do you use the "prime" function prior to starting?

Also the replacement Onan carb I put on mine usually works fine but sometimes will start hard and run rough. When I twist the altitude knob a bit it will fire and run good. Go figure. Gas isn't as stable these days for sure.

Good luck.

[LosLaureles]

I just did a full service on the Onan:
1. Don't waste time and try to rebuild Carb
2. Buy new Carb
3. Pulled Onan and replaced fuel filter: note this is not fun. Onan is very heavy
4. Installed a fuel shut-off valve for winter storage.
None of this is difficult. I purchased a hydraulic lift cart just for this job. Every project needs a new tool and I always wanted one. Just needed the excuse

[chin_k]

Mine is a 2000, and it does not have the prime function, as far as I know.

I already have a shutoff valve on the fuel line, but did not take advantage of it all the time. I think I can try to replace the fuel filter in-place....

[68camaro]

Mine is a 2000, and it does not have the prime function, as far as I know.

I already have a shutoff valve on the fuel line, but did not take advantage of it all the time. I think I can try to replace the fuel filter in-place....

I wpould be surprised if you did not. Over driver seat if you have XL, there should be a boost button, on the on/off switch by frig if you hold down you should hear it prime after few seconds. Also primer is on gen itself.

After new plug, filter and changing oil and regular 2 hr run times with air on (full load), mine keeps running great.

[SMan]

I would replace the carb before having Onan work on it. They "fixed" the genset in my Tioga many years ago and the bill was well north of $500. Didn't last a year.

When I had troubles a few years back with our 2004 Premier I just ordered a carb off Amazon. Tight space but easy enough to install.

I suspect yours may have the prime function.

[caconcourse]

Here are instructions for "priming" the generator, for Chin,

Press and hold the Generator STOP button. After a second or two, the switch should light up, and you will hear a clicking and motor sound of the fuel pump. My generator is a little fussy to start, and I usually hold down the button for 10 or 20 seconds to prime the generator. Then it starts pretty easy, when you press and hold the START button.

You can do the same thing using the switch on the generator itself, and probably the switch in the driver compartment, but I'm not sure.

[chin_k]

All of you guys have newer rig than mine, so I am not sure if we have the same model for the genset. IThe Onan genset does *not* have a light on the switch when I remove the cover. The two remote switches (one on top of the closet, one on top of the driver seat) have the LED light that will light up when the genset is running. I really think it does not have the prime function. Here is the photo... just START and STOP. Any of you have the same model? It makes no noise when I press STOP. Click on the photo will rotate it 90 degree.

[SMan]

Yes that is definitely different than mine chin. Good luck with getting it running.

FWIW After this reply I was motivated to go out and start my genset. It would start, run rough, and die. (All you Onan owners know this sound. ). Again I rotated the altitude adjuster on the carb and then all was good. Only thing I can figure is that gas will crystalize or plug something in the carb. Rotating back and forth clears it. Strange.

[chin_k]

Before I took it apart and replaced the fuel filter and carbo, I decided to add more gas into the tank, even though the gauge said it was already 1/3 full. I added maybe 2.5 gal from a gas can.

It started without problem.

So I guess the pick up tub is either way too high, or the gauge is not accurate. I am going to see if there is a way for me to by-pass this silly "insurance" of fuel reserve so that I can eliminate the issue in the future. I think I heard someone added a Tee to the engine gas line, and allow the genset to get gas in emergency. Let me know if any of you think that this is a bad idea. (fire hazard? possibly empty my gas when the tubing got tugged off?)