Your Generator Won't Stay At One Speed - Now What?

The 5200 Watt Generator

    Since I put in my newest solar charging system, I haven't really been using my generator much at all. I know you're supposed to "exercise" it at least once a month, under load, to keep everything working. Usually I do. But lately I have been distracted and haven't been doing it regularly. Well, yesterday I had a couple of friends over who wanted to see my RV. While showing them around I inevitably had to explain that I run most electrical stuff from the combination of solar and battery, but big energy hogs, like the roof air conditioner, have to be run from the generator. At that point, people always ask, "You have a generator?" Yup, all the time. So I fired it up and showed them. Except this time it began to surge up and down at idle. Very annoying! I've had it happen once before and replacing the fuel filter did the trick. This time, it's my fault. I bet there is some gunk in the carburetor that has to be cleaned. It's not hard, just a bit messy.

Paper Air Filter

First, find your generator compartment and make sure the door stays open by itself. Yes, I have been conked on the head by dropping doors enough to know to check first! Then remove any covers and air cleaners that sit on the carburetor itself. usually these are pretty clearly marked and require no tools to remove. Put aside. We'll clean them while the carburetor is soaking. Now, make sure you have a container that won't melt when you put fuel into it. Styrofoam WON'T work! Glass is fine. The idea here is to drain the fuel from the carburetor, then remove the fuel supply line going to the carburetor and drain it into the container. If you have a carburetor with a drain screw on the bottom, drain that into the container as well -- it will speed up the process quite a bit.

I Have A Short Hose Connected To The Fuel Inlet

Once that's done, you need to be able to get some carburetor cleaning solution into the carburetor itself. The easiest way is to get a short piece of hose the same size as the fuel line and attach it to the inlet you just removed the fuel line from. Then stick the other end in a container filled with cleaner and crank the generator. Usually there is a starter switch in the compartment or on the generator itself. You may hear strange sounds -- it will likely start and stall a few times as residual fuel is displaced by the cleaning solution. There will be more and more smoke as the fuel is displaced by the cleaner. It's OK. Stay away from the exhaust pipe as it may backfire a bit. Once it won't run and you have sucked up a bunch of cleaner into the carburetor, reconnect the fuel line and let it sit. The longer the better. I usually do a few hours. More won't hurt.

Clean Everything!

While it's sitting, clean the air filter with compressed air or (if it's a sponge-type) wash it in a bucket. Remember to let it dry FULLY before replacing. If it's really dirty, get a replacement. Reinstall. You could replace the fuel filter as well, but that may not be needed if you have done it recently. After enough time has passed, it is time to crank the generator over to replace the cleaning solution with fuel. Make sure you have a charged battery and/or are connected to shore power since extended cranking is hard on the battery. Crank the generator over for only 5 seconds at a time and then let it rest for at least 15 seconds between cycles. That will keep the starter from overheating and your batteries from being too overworked. Eventually, the generator will start up and stall a few times until only fuel is being used for combustion. At that point, the idle should get back to normal. After it is stabilized, go turn on a load. I use the air conditioner as it's a pretty heavy duty current draw (Amps) and will work the generator nicely. Let it run for between 15 minutes to half an hour until it sounds nice and smooth.

Put all the covers back on and you're done. If it's still running rough, repeat. VERY dirty or fuel with chunks in it, cannot be cleaned this way. The carburetor will need to be taken apart and cleaned and perhaps rebuilt. Sometimes, you can get away with draining the float bowl (if your carburetor has a drain screw) and then removing it for cleaning -- if that's the only issue. Usually, if it's a clog, it happens in the tiny jets that supply fuel inside the carburetor. Those aren't so easy to get to.


Hopefully everything is working better now. All that's left is to remember to use the generator periodically so fuel doesn't go bad in the carburetor in the first place!

Be Seeing You...Down The Road,

Rich "The Wanderman"
www.thewanderman.com