Gummed Up Carburetor On Generator

[johnjboa]

I have not started my Onan genset in 6 months. Having read all my books again, I realize my big mistake in not starting it monthly. I now suspect the carburetor is gummed up.

What can I use or what is my next step to get this gen back to working condition. I do not use any gas additive. I'm not ready to go to the Onan dealer yet.

Any suggestions will be greatly appreciated.

[zorro2kita]

Have you tried to start the gen? When I bought my coach this winter, the carb was all gummed up - gas was not treated with Stabil - told the seller I wanted a new carb installed which they did - no problems going forward - as you've read others advice, they need to be exercised on a routine basis or treated with Stabil for long term storage.

[johnjboa]

I have tried to start the generator. It turns over but will not continue to run. Can I try spraying starting fluid into the carb? I have added stabilizer to the coach gas tank. Anthing else I can try?

[dickandlois]

John,

I have used Lucas Upper Cylinder Lubricant to improve the performance of both Gas and Diesel engines.

when mixed with ether fuel it rejuvenates the needle and seat area in carburetors, provides upper cylinder lubrication for the compression rings and valves.

It will also clean fuel injectors.

It might help you to get your unit up and running again, The big show stopper is dirt build up in the bowl area of the carburetor. The other issue is the effect ethanol has on small engines and fuel systems, so I use it in my four cycle engines. The two cycle oils help to prevent many of the problems in that type engine.

5 oz. treats 25 gallons of fuel.

Rich.

[dickandlois]

John,

Just a little to see if you have spark. Gas Generator Yes, Diesel NO!

I have used a straw to pick up some gas from a container and dribbled it into the carburetor. Just place it into the fuel place your finger over the top and remove your finger once its over the carb. Keep the straw as perpendicular as possible. tipping it will let the fuel out.

Rich.

[johnjboa]

Rich,

I have not tried the straw thing yet. I have disconnected the fuel line after the fuel filter to check that out and when I push the button to prime the gen, I get a lot of fuel pouring out so I know it is getting plenty of fuel. I have done this several times to make sure I have fresh gas in the hoses and into the carb.

[johnjboa]

Forgot to add this comment. I bought new plugs to install but cannot pull the plug wires off the old plugs. Is there a special toll to use for this or do I just have to pull real hard or get smaller hands to get in there and pull them off.

This generator is in my Winnebago and does not have a lot of room to do things.

[dickandlois]

Tight is being polite, regarding the area.

You might be able to spray some silicon on a paper towel and wipe it onto the plug boots, Let it soak in and maybe add a second coating. IF you can get a grip on the boot, try a little twisting action after you place some silicon on them. Pull on the boot, not the wire its self.

They dry out and can be a real difficult to remove. when you get them off, put a little Dielectric grease inside the boot before reinstalling.

Sounds like the needle is stuck to the seat inside the carburetor! So if you can get it to run just a real short length of time fuel pressure and the fuel should loosen it up. If the carburetor is where you can get to it try tapping on it with the handle of a screwdriver very lightly.

Rich.

[johnjboa]

Well, some success. I got it started with starting fluid and can sustain the run time by squirting more fluid into the throat of the carb. When I stop adding the fluid, the gen shuts down. I am able to keep it running long enough that I used a half can of spray. Maybe a little more than a minute each time. Did it twice.

Any more suggestions please.

[wolfe10]

If you have verified good fuel flow to the carburetor, and it runs when you inject "fuel", that basically leaves a carburetor overhaul or replacement as options.

If you do try any more to run it on starting fluid (which I don't recommend) be sure the breakers are off, as I doubt you are sending "good" power to the ATS and house. Likely wrong frequency as well as wrong voltage. Don't want to damage appliances in the coach.

Brett

[RVerOnTheMove]

If fuel is getting to the genny but not getting into the carburetor I would be looking for some kind of a fuel filter and see if that is blocked or something else between the inlet and outlet that is preventing fuel flow.

[wolfe10]

Wow, Bill and I posted at exactly the same time.

Indeed, it is either his observation or mine.

So, start by verifying fuel flow to the carburetor. If no flow, could be a stopped up filter, bad pump, bad wiring to pump or leak on the hose from tank to pump (suction side leak letting air into the fuel line).

If good flow to the carburetor, overhaul or replace the pump.

Brett

[hermanmullins]

Loosen fitting on the outlet side of filter turn key on. If fuel flows, turn off key and repair Carb.

If no fuel flow loosen inlet side of filter turn on key. If fuel flows, turn off key and replace Filter.

If no fuel flow check pump for loose connection, bad fuse or replace pump. By the way this is a two person job. and protect your face, eyes and mouth. Oh yes, remember to tighten all connections after checking for fuel flow.

It may be an extra expense but I always replace the fuel filter when I change the oil and filter.

Good luck and No Smoking when checking fuel system.

[dickandlois]

John, I see that others have chimed in and they are correct. It there is an input filter,it could be plugged.

The fact that you can keep it running with the spray can puts the problem squarely at the carburetor. The needle and seat must be really stuck if no filter is between the point you opened the fuel line and the carb.

It might loosen by tapping on the carb. You might then get more fuel then needed should it open and it will flood the engine.

That means a carb repair. Small engine shops are next in line.

Have all the information you can glean off the label listing the Model,series number,serial number and so on. You might be able to remover the carb yourself, do not know your skill level. That could save some $$. The idle and mixture will need to be reset and that might take a helping hand.

The settings are important so the frequency and output voltage are correct.

Rich.

[johnjboa]

Thank you all for your input. I have gone as far as I can. I'm going to take the coach to the Onan repair shop and PAY for my stupidity! Again thanks. Safe driving.

[dickandlois]

John, We have all been down this road. The thing is you tried and in doing so are way ahead in the understanding of this system of your coach.

I truly enjoy trying to improve an owners understanding and knowledge.

The best part is, that by you being willing to push your envelope, We all become more informed.

Thank you for your effort and let the group know just what the resolution turns out to be.

Rich.

[BoondockSaint]

I have tried to start the generator. It turns over but will not continue to run. Can I try spraying starting fluid into the carb? I have added stabilizer to the coach gas tank. Anthing else I can try?

Pull the carburetor off the engine. It should be 2 screws or bolts and some linkage. Take pictures if you don't have the freshest memory.

Pull the bowl off of the bottom in a well ventilated area, fuel is going to come out. Spray brake clean or carb/choke cleaner in all the 'jets' you can see them by looking closely.

Reassemble and start.