Run Generator from External Gascan

pward · 11-08-2019, 07:31 PM

Having a problem with the Onan gen set in my Jayco, due mostly to the past owner not using it. Dealer suggested I try injector cleaner to clean the carb but I don't especially want to add that to my main gas tank. Don't know how the gas is plumbed from the main tank, but does anyone know if it would be fairly easy to run it from a 5 gal jerry can or similar? Also found out Cummins doesn't make a carb rebuild kit for the Onan generator, it costs $500 for parts and installation for a new one. Seriously?

MichaelO · 11-08-2019, 07:57 PM

It would most likely be easier to put the cleaner in the MH's gas tank and run it through the generator then trying to get a line from the generator to a gas can just to do that. It couldn't hurt to let some go through the MH's fuel system as well. If you let the main think run low you could then add the cleaner to that and run the generator to get the cleaner through its carb. Once your satisfied with how much has gone through the generator you could fill up the main tank and the cleaner would be well diluted. If it's not going to see much use over winter you could then add some fuel stabilizer to the main tank and run the generator and MH to get the stabilizer through both. Thats what I would do if it was mine.

RogerR · 11-08-2019, 08:43 PM

You might also consider one of the spray in products if it runs. Crud on the intake will also cause some problems. In any case my first thing would be a new plug and clean the exterior of the engine to look for leaks or deteriorated lines or wires.

pward · 11-08-2019, 08:45 PM

Thank you! The main tank is almost full, don't know how much cleaner I would need based on 50 gallons, but I would assume quite a bit. I have also added some stabil to that already, not sure how the two would mix. As badly as the gen is running I might have to use the cleaner more than once.

pward · 11-08-2019, 08:47 PM

Quote:

Originally Posted by RogerR

Crud on the intake will also cause some problems.

Thanks, will do that, good advice.

Bchbum · 11-08-2019, 08:57 PM

Get a 6 gallon boat gas tank with a hose and bulb. Place tank higher than generator. Pump bulb to prime fuel system. Run a hot mix of Sea Foam.

Grumpy · 11-09-2019, 07:12 AM

Quote:

Originally Posted by pward

Also found out Cummins doesn't make a carb rebuild kit for the Onan generator, it costs $500 for parts and installation for a new one. Seriously?

And you can say "Thank you California". It's all because of the environmental laws passed out there which have affected all of us.

foglght · 11-09-2019, 07:16 AM

There are a couple places that make carb rebuild kits. Nobody wants to sell you one because they don't make much money off of it. I bought one a few years ago and it took quite a while to find the place. They are in Texas if I remember correctly.

Most techs at RV dealerships now don't know how to work on carbs so they just want to replace the whole thing.

If you are going to get a rebuild kit, you are going to have to take the whole thing apart and soak the parts for a couple days to get all the springs, float bowl, etc. unvarnished.

Example:

Onan Cummins 146-0457 RV Generator Carburetor Rebuild Kit fits NHM NHE BGM BGE

CAG · 11-09-2019, 09:39 AM

Sea Foam! That is the best stuff going and the only thing I used in fuel that may sit for awhile.

Two ways to go here. You can dump a liberal amount into the tank and run the genny until it runs the way you want it or you can get Sea Foam fogger and follow the directions for cleaning the carb, which is likely the problem.

I have a 9 year old toy hauler (I just sold) and never went without Sea Foam in it. It still fires up like new.

RetiredOne · 11-09-2019, 10:41 AM

Quote:

Originally Posted by pward

Having a problem with the Onan gen set in my Jayco, due mostly to the past owner not using it. Dealer suggested I try injector cleaner to clean the carb but I don't especially want to add that to my main gas tank.

The first question, which wasn't clear in your post, does the generator actually start? Or is it just running rough?

Two different problems that need different solutions.

RetiredOne · 11-09-2019, 10:43 AM

Also, what rig and what generator do you have? Jayco installed different models in different rigs.

On my rig, the gas line comes in from the left side. It would be easy to clamp and disconnect, and hook up a external tank, like a portable outboard tank.

pward · 11-09-2019, 09:31 PM

Yes, I believe I said it ran, just rough. But now, after running some Seafoam through, it won't run longer than 5 or 6 seconds.

pward · 11-09-2019, 09:35 PM

Quote:

Originally Posted by Bchbum

Get a 6 gallon boat gas tank with a hose and bulb. Place tank higher than generator. Pump bulb to prime fuel system. Run a hot mix of Sea Foam.

Thanks but don't have a boat. Won't the gen fuel pump draw gas from an external gas can? Does it need a gravity feed?

Screwby · 11-10-2019, 07:26 AM

Quote:

Originally Posted by pward

Yes, I believe I said it ran, just rough. But now, after running some Seafoam through, it won't run longer than 5 or 6 seconds.

It’s very likely you’ve knocked loose some varnish or crud that is now giving you issues. Sometimes you can get lucky and not have to take apart a carburetor by running a cleaner through it. Sometimes the only way to fix a varnished/cruddy carburetor is to take it apart and clean and or rebuild it. It takes very little crud to block the small parts in a carburetor/fuel pump/fuel filter.

CAG · 11-10-2019, 09:36 AM

Screwby's comment was my first guess. If you want to try it SeaFoam makes a "fogger" that can be used and that may or may not clear up the problem but it would be my choice before I tore into the machine. You might pull the fuel line at the generator to see what that looks like.

I think, and have never done it so it is a guess, you can pull the bulb (aluminum) and see if that is clean.

And, the plug may dissolve on it's own with the SeaFoam in there now.

RogerR · 11-10-2019, 09:36 AM

Try the cheap fix first. You may have fouled the plug. Try a new, clean, properly gaped plug and see if it will run better. If it does than back to the sea foam spray some more. If it doesn't run better than rebuild the carb.

By the way, any small engine shop will rebuild a carb. Your RV dealer may not have the best experience doing this. A shop that specializes on this will be a better bet, cheaper and faster!

Did you pull and clean or replace the fuel filter?

Screwby · 11-10-2019, 10:00 AM

Quote:

Originally Posted by RogerR

Try the cheap fix first. You may have fouled the plug. Try a new, clean, properly gaped plug and see if it will run better. If it does than back to the sea foam spray some more. If it doesn't run better than rebuild the carb.

By the way, any small engine shop will rebuild a carb. Your RV dealer may not have the best experience doing this. A shop that specializes on this will be a better bet, cheaper and faster!

Did you pull and clean or replace the fuel filter?

This x2...any experienced mechanic can rebuild a carburetor

pward · 11-10-2019, 01:58 PM

Quote:

Originally Posted by RetiredOne

Also, what rig and what generator do you have?

2018 Redhawk 22J. The gen is an RV QG 4000 model 4KY-26100 R with what appears to be 3 options according to the data plate.

pward · 11-10-2019, 02:02 PM

Quote:

Originally Posted by RogerR

Try the cheap fix first. You may have fouled the plug. Try a new, clean, properly gaped plug and see if it will run better. If it does than back to the sea foam spray some more. If it doesn't run better than rebuild the carb.

By the way, any small engine shop will rebuild a carb. Your RV dealer may not have the best experience doing this. A shop that specializes on this will be a better bet, cheaper and faster!

Did you pull and clean or replace the fuel filter?

Got it running again but only for about 5 minutes. As soon as a load is put on it shuts down, or a little longer with no load. Suggests to me a marginal fuel pump. I can't run it long enough to get any Seafoam in it so I guess I'll tear the stupid carb apart as I don't have anything to lose.

RetiredOne · 11-10-2019, 02:05 PM

Quote:

Originally Posted by pward

2018 edhawk 22J. The gen is an RV QG 4000 model 4KY-26100R with what appears to be 3 options according to the data plate.

That's the same genny that I have on my rig. I was out looking at it earlier while doing last minute Winter prep.

If you take off the cover, you can disconnect the fuel line right at the carb (clamp the hose first, to keep gas from siphoning/leaking from the gas tank). Then, you can shoot some carb cleaner right into the inlet fitting, and hook up a external hose from a gas can or tank, like a boat tank or similar.

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