Onan Emerald Series gasoline generator...Supposed to run for 30 - 45 minutes a month under load... Generator shuts off when tanks drops below 1/4 tank so generator can't run coach out of fuel...Don't want to keep stale ethanol fuel in bus to exercise generator... Not convinced fuel "stabilizers" work with ethanol and not easy to get to good fuel... Thinking of adding a small auxiliary tank and bypass valve for the sole purpose of exercising genny. Looking for input. Does this make sense? Ideas on requirements / issues, etc..Thanks!

I've been using that Sta-Bil stuff forever and have never had a problem with it and E fuel stored for over a year...I use it in all my 5 and 2.5 gallon gas cans that I keep for the lawn equipment, home generator, etc.. (I keep 2- 5 gallon and 3- 2.5 gallon cans for storage at home)I use this for the entire year. After a year, if I haven't already used it, I'll just put in one of my vehicles and refresh with new gas and Sta-Bil.I do try to run it out of the gas tanks it's in, but once I left it too long in the Honda gen (probably over 2 years) and had to drain it out, but once I put fresh gas in, the gen ran fine.Anyway, your aux tank sound fine if you can rig it up safely...Even at a 1/4 tank, that's probably around 25 gallons of gas in the rv's tank...Good luck!Mitch

i would use sta-bilor maybe just add (2) gallons of fresh fuel every month when exercising the gennywill keep it freshIF you install an extra tank, what is going to be in the main tankit will still have ethanol anyway, very hard to get pure gasoline any moreburn some old, then add (2) gallons new fresh fuel

Hi,I had better luck with Sea foam than with Sta-bil. That applies to the engine as well as the generator.Since my generator has its own tank, I do use premium fuel.Since the generator draws from the main tank, you could do the last two fill ups of the season with premium.

last fllup of the season (75 gallons regular gas) I dump an entire bottle of Sta-bil in the tank.From that gas station to my house is 18 miles. I do this with the generator running to make sure the Sta-bil gets everywhere its' supposed to be.Then, every 2 weeks or so, I start the motorhome engine and the generator, let them run for about 1/2 hour. The gas gauge hardly moves during the winter.No problems. Does the Sta-bil really work? Do I really need to do this? Don't know. But I feel better.FWIW, my Harley gets a full (5 gallon) final fillup. No Sta-bil. If snowbirding, it sits for 3+ months. Fires up on the 2nd hit of the start button. Runs fine.

Exercising generators and Diesel engines every month is a waste of time and should go under urban legends along with changing your car's oil every 3000 miles. How can all these portable generators survive without being exercised every month??? I have a portable welder that's 50 years old and it sits outdoors and it can be years between uses. Its sat so long that I have to touch the leads to a battery to re-magnetize the fields to get it to weld. I have a portable generator that's 40+ years old and gets used every 5 years...maybe. My 14 years old 10k generator has never been run every month...doing that would interfere with sorting my socks.I agree the gas today sucks and needs to be stabilized if storing for more than 4-5 months. I would shut off the fuel supply to a gas generator...add a valve if necessary and then run it till it stops. Open the valve and crank it up next summer and Go Camping. Putting the spices in alphabetical order will be a better use of your time than running a generator every month.:S

Need input: RE: 2nd tank for gas generator "exercising"

31 Replies

mlwinnig
Explorer
Jan 02, 2018
Thanks. I like keeping gas as fresh as possible but understand advantages of full too. Issue with my setup is you need 1/4+ to run genny as it shuts down at 1/4 to keep genny from running rig out of fuel. Will need either more parts or service in Spring as I don't think genny will respond to load requests to raise output (couple parts fell off). I think throttle return spring may be weak too and should be replaced. Interesting thing is surging is now gone running at idle with StarTron.

I think I will ask at Cummins/Onan Coach Net service center nearby. They are great and must know!
tropical36
Explorer
Jan 02, 2018
mlwinnig wrote:
Onan Emerald Series gasoline generator...

Supposed to run for 30 - 45 minutes a month under load...

Generator shuts off when tanks drops below 1/4 tank so generator can't run coach out of fuel...

Don't want to keep stale ethanol fuel in bus to exercise generator...

Not convinced fuel "stabilizers" work with ethanol and not easy to get to good fuel...

Thinking of adding a small auxiliary tank and bypass valve for the sole purpose of exercising genny. Looking for input. Does this make sense? Ideas on requirements / issues, etc..

Thanks!

I like having a full tank, gasoline or diesel and don't worry about it getting stale, especially with gasoline.
But, if you insist, then just get yourself a 6 gallon boat tank, with a length of hose attached for disconnecting the genset fuel line and attaching the temporary. May have to plug the main, while you're at it, but no biggie and have done it lotsa times when troubleshooting. Have even done so, with a gallon milk jug and all that's really needed for this.
wildmanbaker
Explorer
Jan 02, 2018
Sam Spade wrote:
centerline wrote:
the red stabil is useless on ethanol fuel.....

Interesting that the company that MAKES it does not say that.

They say that it was reformulated slightly a few years back to work with ethanol.

I'm sure that we all would appreciate you giving us a reference to look at that says it is useless.

He may have had an "old" bottle stabil he was using. I know I keep buying more of Seafoam, Stable, Brake clean, and carb/fuel injection cleaners, as when I see them, I grab them, not being able to recall if I still have any, and how much. If I find I have them, I rotate the oldest products to the front, to use first.
Old_Man
Explorer
Jan 02, 2018
Why not do solar, instead?
Sam_Spade
Explorer
Dec 24, 2017
centerline wrote:
the red stabil is useless on ethanol fuel.....

Interesting that the company that MAKES it does not say that.

They say that it was reformulated slightly a few years back to work with ethanol.

I'm sure that we all would appreciate you giving us a reference to look at that says it is useless.
RLS7201
Explorer II
Dec 23, 2017
dougrainer wrote:

YOU do NOT work at an Onan or RV service center. It can take less than 60 days for fuel to varnish and ruin a Onan Carb. Diesel's? never had a problem, but how hard is it to start your genset once a month for 15 to 30 minutes?. As to Portable gensets, SAME THING. Even your Lawn and Garden Gas powered equipment will be ruined in 30 to 90 days if you do not run them or add stabilizer to their fuel tanks. Doug

PS, I have a LOT more experience with these things than you do.

Doug, you need to buy your E10 here in Missouri. My lawn equipment and 7K Onan sit for up to 6 months at a time with no ill effects to the carburetors or fuel injectors, with NO fuel additives.

Richard
DrewE
Explorer II
Dec 23, 2017
centerline wrote:
the red stabil is useless on ethanol fuel... the blue MARINE stabil is formulated for stabilizing ethanol fuels and is also more concentrated, so the same size bottle goes farther than the red stuff does..

Why do you say that red Sta-bil is ineffective with ethanol-containing gasoline? I don't claim to be an expert on the differences between the various formulations; however, my bottle of red Sta-bil is explicitly labeled "Effective in all ethanol blended fuels," and I would think the maker would have a reasonable idea on what it works in.
centerline
Explorer
Dec 23, 2017
the red stabil is useless on ethanol fuel... the blue MARINE stabil is formulated for stabilizing ethanol fuels and is also more concentrated, so the same size bottle goes farther than the red stuff does..

not all states/area have this option, but when laying up the RV for winter, filling the tank with ethanol free fuel has benefits that far outweigh the extra cost.... and a bit of seafoam added to the ethanol free fuel will stabilize it and will also dissolve any gum and varnish that has built up from running the ethanol fuel during the rest of the year...
mlwinnig
Explorer
Dec 23, 2017
Update: Went with StarTron fuel additive. Seems awesome! Worked it through coach and genny carbs. For now just trying to start and run everything for 30 - 45 minutes every 3 - 4 weeks or so (when Temps. are up a bit). Last run was below 40F. Takes about 7 - 10 seconds for genny to fire up but she's running great! Surging issue no longer there. Not sure she will support a high load as a couple of pieces on top are missing and I think spring is weak. I think this is what raises output to respond to demand. But for winter storage I think we are good. Thanks for all the inputs!
Cobra21
Explorer
Oct 20, 2017
Many generators won't even start in the winter unless you use proper
weight oil. I have the specified 30 weight oil, unsuitable to start at minus temps.
Brian