Fuel cutoff solenoid for Onan gensets?

[mlts22]

For storage, I've wondered how useful it would be to have either a fuel petcock valve on the line, or if one wanted to get fancier, a solenoid activated fuel valve (so it could be turned on/off from inside.) This way, the generator can be shut off via this method, which would run the fuel line dry, as well as the carb bowl.

Would this be worth doing as another way to protect against fuel varnish? I know this helps with portable generators since if they get run dry, there is no fuel to go bad inside the tiny jet areas.

[Pipeman]

I have owned an Honda 3000. Drained the carb for the winter. I have an Onan 4000 now. I fog it, then drain the carb. I have been doing this since buying it. The Onan doesn't get exercised. It sits from October until May when I get it ready for the camping season. Now the gas for it always has stabil in it. When not in use for the genny it gets used in the lawn mower,the snow blower, the chain saw and whatever else I need it for.

[Dusty_R]

Our 4000 watt Onan we only use once or twice a year. I added a switch to the electric fuel pump and when I know we are not going to use it again for a while, I just turn the pump off and let the generator run out of gas.
Been doing this for several years and never had a problem starting it when needed.

Dusty

[MrWizard]

i don't know about NEWER more recent models of Onan genset
but IIRC the older models I'm familiar with have a fuel shut off solenoid that is only 'Open' when the generator is running, and is always closed when the generator is off
it is/was there to protect the genset and prevent flooding and gas loss as the RV traveled with the genset OFF

[Chinolbz]

Like ernie1 said, drain the carb. No big mystery, it just works. Chino

[64thunderbolt]

try some seafoam along with stabil and no issues. No draining.

[marcsbigfoot20b]

ernie1 wrote:
On my 2800 Onan I just drain the carburetor bowl via the phillips screw in the bottom. Always works well. I've tried using Stabil and leaving some of the treated gas in the carburetor but would have a hard time starting the generator later on and I'd get backfiring too. I don't exercise the generator at all when it's stored inside my garage and have not had any problems with it starting months later and no backfiring.

Same here, on my EU2000i. 3 months of sitting and it wouldnt start. I would have to pull the carb and give a quick blast with carb cleaner. Now I simply drain the float bowl and try to start 5 or 6 times in the off position to pull any residual fuel through the jets. Starts up on the 3rd pull with choke now.

Thankfully my built in Onan 2800 microlite is propane, so no issues there.

[ernie1]

On my 2800 Onan I just drain the carburetor bowl via the phillips screw in the bottom. Always works well. I've tried using Stabil and leaving some of the treated gas in the carburetor but would have a hard time starting the generator later on and I'd get backfiring too. I don't exercise the generator at all when it's stored inside my garage and have not had any problems with it starting months later and no backfiring.

[MEXICOWANDERER]

WHITE GAS can stay in a carburetor for twenty years and it will not gum, ever.

The trick of course is how to make it easy and convenient to run that generator the last fifteen seconds on white gas safely. After learning this trick from professional loggers treating their chain saws before storage, I have had 100% fewer restart problems with everything from saws, to lawnmowers, to you guessed it, generators, works with 2-cycle BUT DON'T ADD OIL to the white gas. A few seconds of operation with pure white gas will not hurt things in the slightest. I have restarted chainsaws after six years of storage on the first pull using this little trick.

[mlts22]

For short term storage, running fuel with Sta-Bil through the lines, then letting the line post-valve run dry. For long term, I'd run the line dry, drain the bowl, then use OnaGard and fog the genset.

[Kpackpackkelley]

This is a tough one . I used to run carbs dry on small engines but a good bit of gas stays in the bottom of the bowl and aluminum sweats it mixes with that gas so the next time you run gas in it it just mixes with it .
On lawn mowers or gens that are gravity fed i leave the fuel full in the carb but cut the petcock off so if your are hauling it when it bounces up and down it will bounce the float and flood the engine . When i'm ready to start it back up drain the bowl and open the petcock to fill the bowl back up . A full bowl while your not running it will not sweat as much .
On a gen with electric fuel pump i would leave the carb bowl full for the same reason but you don't have to worry about bouncing up and down because you usually have a fuel solenoid . Same thing if its down a long time just empty the bowl right before your going to run it again .
When you empty the carb bowl on new start you can open the petcock or prime button and run the gas out of the fuel hose to till the gas looks good you can tell by the color .
If its going to be yrs before you run it yes empty the bowl take bowl off and wipe the bottom out clean blow a little light air up the main jet to get it dry . Hope this makes sense .

[BruceMc]

There's two trains of thought on this:
1) Run dry
2) Treat and store full

Problem is, there's always a drop or two remaining in the critical jets even when shutting down the fuel input. In my opinion, it's better to treat the fuel with stabilizer and run the equipment sufficiently to pull in stabilized fuel, then store full or run dry, but at least the fuel has been stabilized.