Generator Carb Problems

[UncleDave]

How much is one of the carbs? How hard to replace? Are they available?

Not the same probably as the RV mounted ones.

The carb on my snowblower was leaking and engine surging. Rebuild kit was $12. The whole new carb with primer, hoses, gaskets, throttle handle, choke knob was $18. Yup replaced it.

My old hand me down generator with Briggs motor I couldn't get a carb for under $150 and even they were limited. I took it apart and fortunately was able to clean it up. Learned from those like Uncle Dave. They all have fuel shutoffs now. I also run some TruFuel or VP Racing through them first, then shut fuel let it run out. Restart 2-3 times as it sits, then drain the bowl. No matter what fuel it will evaporate out of bowl sitting and leave all the junk. Old snowblower had issue every year (sat in shed in sun). Shop finally said We love helping you but all we do is clean out your red Stabil every time". Told me to do as above and no issues since. I still go there for other services, parts, 2 stroke and VP ethanol free. Hard to find an honest place, I try to support those that I do.

It was the RV unit - I had it in a toy hauler.
I think it was about 150 last time I bought one, there was no rebuild kit when I looked.

 

[TheLastWord]

If you desire a gasoline additive that will clean a carburetor while the engine is running, use Berryman B-12 Chemtool. It is orders of magnitude more powerful than Seafoam.

I had a problem with the carburetor on my gasoline powered 5 KW generator related to varnish from fuel, and by using Berryman B-12 Chemtool in an aerosol can, I was able to clean the varnish and other crud out of the carburetor and avoid having to pull the carburetor and rebuild it a handful of hours before Hurricane Sandy approached Maryland and knocked out our power. I also added about 8 ounces of Berryman B-12 to every 5 gallons of gas, and the generator ran flawlessly for 60 hours straight after we lost power.

Good Luck!

Every better is Berryman B-60. Heavy duty stuff.

 

[garageman402]

Every better is Berryman B-60. Heavy duty stuff.

So now there's B-60 for "high mileage" 60,000+ miles? How different from B-12 is this? They advertise H.E.S.T. solvents, & of course PEA. They advertise "dissolves carbon", so maybe I should put this in my 195,000 mile Buick?

 

[TheLastWord]

So now there's B-60 for "high mileage" 60,000+ miles? How different from B-12 is this? They advertise H.E.S.T. solvents, & of course PEA. They advertise "dissolves carbon", so maybe I should put this in my 195,000 mile Buick?

In my experience, just more concentrated. I have never used it in a car, just for OPE where it works much better.

Saved me from cleaning and rebuilding carbs. Be patient, let it work with gas mixture. YMMV.

 

[CarDoc66]

Convert it to propane. Four of my generators run on propane, I never have to worry about storage or finding a carb.

 

[97prizm]

We have a Cummins Onan QC 4000 generator on our RV that doesn't get a lot of use. It was last run in August, & has been inactive ever since (about 7 months). Now it won't start. Our RV dealer doesn't work on generators, they sub it out, & there's warranty questions, so the shop foreman tried to get it going. He said when they sit like that, the carb gets gummed up from old fuel. He got it to run on carburetor cleaner, but that's all. He advised taking the fuel hose off & running Sea Foam through it. The hose is attached with a crimp clamp which I don't want to tamper with if it will void the warranty. The carb bowl has a drain valve which I have opened, & primed, fuel comes out when the pump is running. So we know it's getting fuel, we know it's getting spark, because it runs on carb cleaner. I attempted to spray Sea Foam & Gumout carb cleaner in through the drain plug.

The generator feeds off the main fuel (gas) tank, but only down to 1/4 tank so you don't get stranded. This is a 60 gallon tank, so I need to treat the whole 60 gallons to get it to the generator.

My question is what kind of fuel treatment would I use? Sea Foam is oil based, not sure if it would be effective. I'm assuming a PEA additive would be ideal? Would (3) 20oz bottles of Techron be a good start? I can get it to fire by holding the choke closed after priming, but it only lasts a few revs with choke closed or open.

Not sure if an RV carburetor is Similar to a lawn mower carb but. My local ope mechanic showed me a couple of tricks when my mower acted the same way. Some carburetors have a main jet or port and some but not all have an idle or starter jet. Sometimes the smaller jet gets gummed up keeping it from starting

 

[UncleDave]

Convert it to propane. Four of my generators run on propane, I never have to worry about storage or finding a carb.

In a fixed location propane is great.

Propanes energy density in an RV genset application blows chunks, and given your fridge and heat are powered from the same fuel source putting a genset on that is really going to limit run time in a dry camping scenario.

If all you do is go from campsite to campsite it's workable.

 

[dumkid]

Not sure if an RV carburetor is Similar to a lawn mower carb but. My local ope mechanic showed me a couple of tricks when my mower acted the same way. Some carburetors have a main jet or port and some but not all have an idle or starter jet. Sometimes the smaller jet gets gummed up keeping it from starting

It's almost identical. The onan carbs have a main and idle mix screw, while many carbs are non adjustable unless you have jets that fit.

I have a 2000w onan from a 92 motorhome sitting in my yard and had to un-gum the carb. Now it runs good.

 

[fantastic]

See if you can go to a Cummins location if it's under warranty. Have them deal with it. Excercise the generator every couple of weeks for 2 hours w/a load like the Air conditioner. Definitely treat that RV tank right before you fill up w/injector/carb cleaner & gasoline stabilizer always. Also you could use 91 if you think what I mentioned isn't enough. That's the downfall of those gasoline Onan's that I luckily have the benefit of not experiencing w/Propane Onan. Just keep at it & you'll figure it all out.

 

[SammyChevelleTypeS3]

This gen is famous for this, the micro quiet 4K. Every gen set shop has a garbage can full of these carbs.

At this stage with this genset id replace the carb and religiously drain it going forward.

I wouldn't worry so much about the treatment of the fuel if you drain the carb religiously.

Awesome advice. Always best to do "preventive/predictive" maintenance so we do not end up having to do "oops/repair" type jobs due to something we failed to do. I always disconnected the fuel lines and let my 150 Yamaha + 90 Evinrude engines idle on the trailer until they stopped running before I pulled the boats out of the water. So I never had to fight with fouled/cruddy or plugged up carbs.

 

[Doc8404]

Startron additive.

Add a fuel shutoff valve and run dry if you can.

E0 fuel.

 

[The_Eric]

I'm going to be dealing with basically the exact same generator. It came to me last year with an Amazon clone on it and running like complete poop. I could see that the carb had been replaced and messed with, so I replaced it again with basically the same results. This thing is WAY TOO RICH. It barely begins to run ok with the altitude compensation needle cap removed and it screwed all the way in. It'll pull a load if you can get it to transition to the main, but it's rich (can smell) and a lot of times it'll stumble pretty bad and not pick up the RPM.

My plan is to remove the main and pilot jets, plug and re-drill them. Right now the main is about .050" and the pilot is about .022". I plan on taking about 15 to 20% fuel from the main and 15% fuel from the pilot. That means going to about .046 to .048" ish on the main and .020" on the pilot. We'll see how that treats me...