Do newer generators need to exercise regularly?

I recall the first portable Generator I ever bought. A Generac 1000. A True 1,000 watt enclosed Generator. Noise and fuel consumption comparable to a Honda EU-2000i but only 1,000 watts and .. much lower in cost. I liked that genny and would love to get it back and send the legs it grew to the hotel graybar.

But when it was new some of my Electronics "Objected" to the output waveform

After a tank of Gas.. No further objections (The tank was feeding a light)

WHY: Well it is not just the fuel. There are a few electronic parts that need exercise. also brushes. slip rings and the like need to be polished from time to time. Exercise does that. Sitting in the box on the shelf in the store.. No Exercise.

Put seafoam in your fuel and run it to draw thru carb. You won’t have any issues with gumming up your fuel system. I’d run ionce a month to exercise parts and lubricate.

I can see only two reasons to run a generator for exercise. One, the fuel needs to be kept fresh, but draining will be even better. And two, some generators depend on residual magnetism to begin generating.

I fuel my home generator once a year for a test run. My Hondas are fueled and test run at the beginning of the camping season. All three are drained of fuel after the test runs. Any more exercising than that is, in my opinion, a waste of time.

garyemunson wrote:
I'd much rather find out the generator won't start when I go to "exercise" it at home than to let it just sit then not start at the 1st campground on a long trip.....

Says it all ;)

SidecarFlip wrote:

2oldman wrote:
My Hondas just need the bowl drained to sit for long periods. I've never exercised them.

If it's electronically excited (inverter) you don't. If it has slip rings and brushes, conventional genny, you do. Reason being is to keep the slip rings from tarnishing and to keep the magnetism alive in the armature.

Think I'd exercise those Honda's anyway. Keep the rice from clogging the mufflers.:p

The part I find suspicious is that the recommendation to ‘exercise’ an Onan didn’t begin 90 odd years ago when David Onan began building them, ironically for a friends summer cottage so it only ran a few months a year, it only started after Onan was purchased by Cummins.

A good friend of mine has a summer cottage on an island in the Great Lakes. His electricity comes from an Onan removed from a derilict motorhome. For many, many years it runs long hours over the summer then gets run dry of gas and left for 7 or 8 months then put back to work. I’m still never been an issue.

My own motorhomes were both parked for years before I bought them and VERY low hours so obviously NOT exercised regularly. Neither one of them gave me any grief when I lit them up.


I don’t believe that ‘exercise’ is needed by anything but the bean-counters in the warranty department.

I'd much rather find out the generator won't start when I go to "exercise" it at home than to let it just sit then not start at the 1st campground on a long trip.....

In the case of the Onan 4000 there is another reason to run it periodically, these Onan RV generators have brush style generators, the carbon brushes run in slip rings on the rotor, if left sitting, particularly in a humid environment tarnish builds up on these slip rings. When tarnish builds up it increases the resistance of the circuit, which then in turn tends to burn out the voltage regulator on the combined voltage regulator / control circuit board. (older models had a separate circuit board for voltage regulator and control board).

ktmrfs wrote:
Now the newer honda 2200 have a "run dry" feature you can use when you shut it down to keep the generator running till it runs out of fuel in the carb. It shuts off the fuel pump.

You easily add the same feature to an older honda 2000 as well.

I added this "run dry" feature to my Honda 2000. I bought this Shut Off Switch. I unplugged the wire that grounded out the generator and replaced it with this switch. If I leave the switch ON, the generator now runs till it runs out of fuel. I have the option of turning the switch off for immediate shut down. (The switch is currently inside the generator case. When the generator is out of warranty, I will drill a hole and mount it.)

If the engine uses steel or iron parts lubed with oil, you should run it from time to time for no other reason than to scrape the rust off before it welds things together so they can’t move.

The manual for one of my generators has a section mentioning what to do if it hasn’t been run in a long enough time to where the field coils have lost their residual magnetism so they can’t get the current started. It involves shorting a battery across some terminals briefly. That sounded exciting enough to me that I determined to avoid the issue entirely and just run the thing for a half hour every month or so. For what it’s worth, that generator is only 3 or 4 years old.

Onan suggest you exercise their 4000 (new and old).