Genset carb upkeep:  drain it and/or exercise it? Both?

It all depends on how frequently you use the generator. It only needs exercised once a year, and only needs drained if it will be stored over a month. Also, snake oil is a waste of money.

My Honda 2000i is over 12 years old with lots of use including 2 years full time travel. I have never drained the carb, and never added Seafoam. I did clean the air filter once or twice and changed the spark plug after about 8 years of use. I do try to remember to run it once every few months but often forget. I change the oil every year or so.

It runs great.

Unless Honda has changed to a bad idea, that carburetor is designed to be drained. How is that for an answer. If you plan to leave it alone for a long time (more than a couple of months) or just don't know when you might want it again. Get some "Fogging Oil" or Marvel oil. Get it warn and turn the fuel off. As it starts to sputter, fog the engine until it is stopped. Now, turn the crank until you feel compression. This means both valves are closed (and the points as well if it has). Now drain the carburetor and put the machine someplace safe.

Apart from the fogging, this is what it used to say in all the Honda manuals and there are reasons for all of it.

The old thing about running the electric end at load to warm the windings is left over from WWII. Everybody has used much better varnish on the windings for the last 60~70 years.

Matt - a ship's engineer by trade

The point of running a generator under load every month, according to Onan anyway, is to produce heat in the windings and help dry out moisture. It has nothing to do with a carburetor getting gummed up because Onan recommends the procedure for propane powered generators.
I have no idea if Honda recommends this same procedure for the same reasons. I have no idea if, as Matt suggests, this procedure isn't necessary anymore. I know it was in the manual for my 2003 Onan RV generator.

You can buy a kit from Hutch Mountain that allows your Honda to use all of the fuel in the carby before shutting down. Using this option after a trip when you don't plan to use the genny for a while saves you draining the carburetta manually. I fitted one as I didn't want fuel residues gumming the carby up.

I owned a 4000 W Onan. I always used Stabil in the gas. When it was done for the season I would drain the carb and forget it until the next camping season came around. Now I have 2 Honda 2000s that I can parallel run if needed. I still use Stabil and I drain the carbs at camping season end, fill the gas tanks, put the covers on them until next camping season then I drain the oil and start them up. Been doing this for years. No exercising in the off season. Works for me.

According to the Honda manual all that is needed for 2-6 months of storage is to use fuel stabilizer. If you really want to give it extra TLC, I would use alcohol free gasoline for storage.

Fuel Stabilizer and Ethanol free gas is all I do to mine.

Yes, if I could find non-ethanol gas in California, I would use it. I think that there is non-ethanol aviation gas, but I don't think that it is available to the general non-flying public.

Stabil helps, but I used to get "GCS" (gummy-carb-syndrome) even with Stabil, until I learned how to drain the carb after every use. You know you have GCS (which is an acronym I have just invented -- you're welcome!) when your generator starts to idle very rough, surging and "loping."

So far, I am not hearing anyone say that I need to first exercise the generator monthly and then drain the carb?? Is there a consensus?

KD4UPL wrote:
The point of running a generator under load every month, according to Onan anyway, is to produce heat in the windings and help dry out moisture.

That is a pretty much "CYA" statement.

The "windings" of all generators just like any good AC motor are DIPPED in a INSULATING AND MOISTURE PROOFING VARNISH..

The windings are then heat cured in an oven and then HiPot tested to ensure no electrical leakage or breakdown of the insulation before windings are installed.

As long as your gen is not sitting out in the yard in the rain and the windings are not directly flooded by water there is no "need" to "produce heat in the windings to dry out the moisture"..

Besides, the very second you shut it down the moisture held in the air around the gen WILL start redepositing back on and into the windings.. You simply cannot fight the fact that the air holds moisture right up to 100% humidity.