Tuesday, September 28, 2021


For good health, exercise … your generator!

Base image courtesy Travelers in the Middle East Archive (TIMEA) on wikimedia commons.

Courtesy of Onan Generators

Do diesel generators need exercising like gasoline generators?

Yes, regular exercise helps lubricate the seals and engine components and keeps carbon from building up. Regular exercise also heats up the generator windings and removes or expels excess moisture. In sets equipped with brushes, exercising helps prevent corrosion build up on the slip rings.

How often should I run my gasoline generator to keep it in good condition?

It may seem strange that not using a machine could cause performance problems, but with RV generators that’s exactly the case. Regular “exercise” is an important part of keeping your generator healthy. Lack of use can cause moisture build-up and fuel system damage that makes it run poorly. In fact, in as little as 30 days, the fuel in gasoline-powered generators can begin to break down into gums and varnishes that clog the fuel system. Fuel varnishing results in hard starting and surging. (A surging generator never settles at a stable operating speed.)

To prevent such problems, we recommend running gasoline generators at a minimum of 50 percent capacity (for example, 2000-watts, or one air conditioner for a 4000-watt set) for two hours at least once every four weeks. A long two-hour exercise period is preferable to several short periods.



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Gene Meiser
1 year ago

I cannot get my Onan 4000 generator on my 1998 24′ Class C to start. I just had it repaired and serviced a few weeks ago and have run it a couple times since. (I am a part time RV’er). I just filled the gas tank, and it turns over but doesn’t start.
Any easy suggestions? Thank you!

1 year ago

I have never exercised a generator in 30 years and never had a problem. Run it dry or drain the carb and you are good to go. Also if they are not used much use good synthetic oil and you dont need to change it. Oil doesn’t go bad inside the genset when not used.

1 year ago

I always use ethanol free fuel. I still add stabilizer and shut down the fuel and let the carb empty. No problems in over 20 years with this method in all of my small engines.

Bob Weinfurt
1 year ago
Reply to  Bob

I’m a retired mechanic. Using ethanol-free fuel is a big plus, running the carb dry is too. But I’ve found some gasoline stabilizers can cause problems, especially with pre-mix, carbureted 2 cycle engines.

1 year ago

When storing my generator after use I drain the gas tank then run it till it runs out of gas draining the carburetor bowl and gasoline from the gas tank. Been doing this for 40 years without any issues about the generator not running properly. Another tip once a year even if you didn’t use it much or at all change the oil in it.

1 year ago

Suggest adding stabilizer to ur gas generator fuel tank – keeps moisture out and does not allow fuel to break down. Do not understand why this “😍cheap” option not noted in article.

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