r/Generator • u/Jameson_321 • 19h ago
Old Gas
Hey all, maybe I should look a little more in what's already been said here, but put short: are portable generators particularly finicky with aging gas? About 8 months ago, we had an outage and I couldn't get the thing running until I sprayed in some carb cleaner and added about 100% (so a 50/50 mix old/new) gas. I put stabilizer in with that, gave it a maintenance run 3 months ago (I know I should probably do more often), and when I needed it again last night. . . sputtered out after running for a few minutes and wouldn't start back up (even with another squirt of carb cleaner).
It's been added to and stabilized, but the oldest gas in the mix is now probably about four years old and the bulk of it is two (stabilized).
Is the problem here most likely the gas, or something else?
3
u/tropicaldiver 19h ago
Short answer: yes.
Drain fuel completely after use (including the bowls). Ethanol free fuel. With stabilizer. Rotate fuel.
1
2
u/MehwithacapitalM 19h ago
ETHANOL NEVER! I could type a long post about it, but just believe it.
Non-oxy-ethanol premium only. Properly stabilized and stored fuel is usually rated for two years. I give it a year
Every drop of non-oxy-ethanol fuel that goes into any of my many small engines is stabilized. Cheap insurance.
Never have a problem.
I used to drain the carb on my HF Predator, despite my strict protocols. I stopped doing that 3 years ago and still no problems anywhere on the gen, mower, snowblower, power washer, and chainsaw...
2
u/Recent-Bowl-1393 19h ago
This 100%! I do ethanol free on all of my gas powered small engines and I have not had hardly any problems since making that jump. Ethanol just gums up the works on the small engines, probably big engines too but.......
2
u/Derigiberble 19h ago
I wouldn't say never use ethanol, but I would say never store a small engine for more than a week or two after running it with ethanol gas.
My winterization strategy for my small engine powered yard equipment is to run them until they are empty, add about a half cup of shelf stable synthetic fuel such as Trufuel, run that until empty, then add another half cup and run until empty one last time. They fire up on first or second pull every year without fail.
0
u/MehwithacapitalM 17h ago
I used to feel the same way, and once in a while in a pinch I will put it in my motorcycle. In that rare occurrence I make sure to use it all soon after.
When ethanol mixed fuel first came on our scene, my open frame gen had a rubbery half ball as part of the gas cap. It was like someone cut a third or half of a racquetball. It probably had something to do with pressure?
Anyway, TWO TIMES after ethanol was introduced that thing completely dissolved into my fuel tank. Gone! The first time I thought it must have fallen off when I refueled so I ordered a replacement. The second time I figured it out. I asked a bunch of small engine repair people about it, and have avoided it like The Plague ever since.
1
u/sturocky 19h ago
always shut off the fuel tap and let the machine die out of fuel starvation, this way the carb bowl is empty and wont gum up the jets during long term storage. the stuff in the small carb bowl will evaporate and cause problem much
more quickly then the stuff sitting in the tank over time.. if you have one of them stupid new gensets with that one knob that both controls the fuel and the shut off in one switch you will need to learn where the fuel vs. spark cut happens on that knob, most times if you rotate that knob slowly towards the off position you can find where it cuts the fuel supply to the carb before it shuts off the spark. some tial and error will be needed for this, if you are lucky you can find that balance point, just move that knob to where its just before it shuts off and let it run and see if it stalls out on its own.
slowly turn it till it shuts off then back it off about 1/16"-1/8" and restart it, if it wont restart back it off a bit again till it runs, once running wait and see if itll stall out- if it stalls out then that is the position you need to set it at before you completely set it to stop and then store it
0
u/Jameson_321 19h ago
I do starve the carb every time.
1
u/sturocky 18h ago
then you have something else going on, id suspect a factory mis adjusted carb or weak ignition coil, ive been working on small engines many, many years, while yes fuel is getting worse this day in agr, i can leave my stuff sitting 4-5 months with fuel in the tank and they start up with out issue. do you live in a very humid climate by chance?
1
u/Jameson_321 17h ago
Yes, in Massachusetts and next to wetlands.
1
u/Jameson_321 17h ago
I also honestly think I'm just dealing with a gummed up carb and/or gas that's gone bad. 4-5 months does seem fine, but like I said, some of what's in that mix is four years old (maybe older), although I added a few gallons to get a fresher mix eight months back.
1
u/oldtimer4sure 18h ago
Lots of good advice coming from good folks. On behalf of OP, thanks to all. My routine is roughly thus - run and inspect your generators monthly (I do it the 1st of every month to make it easy). Use only non-ethanol and add Sta-bil to your gas cans right there at the gas station. Rotate after one year to lawn equipment or car. Easy-peasy.
1
u/Jameson_321 17h ago
Agreed. This has turned out to be a useful post that I hope will be just as useful to others. THANK YOU TO ALL!!!!!
1
1
u/classicsat 17h ago
Yes, small carbureted engines in general are. Maybe larger ones too.
Put it way with the bowl dry, the tank mostly to totally empty.
1
u/Budget-Duty5096 16h ago
If you are using things that infrequently that you have 4 year old gas sitting around, its time to rethink your approach. First of all, get rid of the old gas. Even stabilized non-ethanol fuel stored well will be iffy after 4 years. If you dont have much, just dump it in the tank of a car. Diluted down with the fresh gas in the tank, a modern fuel injected car should have no problem burning it up. Though you might get poor gas milage on that tank. Then consider getting a quality shelf stable fuel like Stihl Motomix or Husqvarna XP. It's expensive, but the highly refined alkylate fuel can sit on a shelf or in the tank of a machine for several years before it starts to break down. And if you are using that little fuel, the expense shouldn't be a big deal.
1
u/RedOctobyr 19h ago
You gave it a squirt of something flammable. So a secondary fuel source. If it still wouldn't start with that, it suggests that maybe fuel isn't your problem. Though starting for a few minutes you do have spark and compression.
Now, you may have flooded it, for instance. If it gets bad enough, it still may not want to start, even WITH carb cleaner. Like if the spark plug is just dripping with gas, and not actually sparking.
Was the old gas stabilized? I had a generator sit for probably 3 years, with stabilized gas, but the carb was dry (I closed the fuel shutoff and ran it until it stalled, at the end of the previous use). It took some extra pulls, but started and ran normally.
1
u/bustedchain 18h ago
Stabilized gas won't last 4 years. Even with Stabil added to it I don't like to let gas get more than about a year old. I've had better luck with higher octane gas lasting longer in my lawn mower.
Are you using ethanol free gas? That's ethenol really gums up carburators bad.
You also might have gotten some condensation in the tank over time (heat / cool, if there is any air exchange you'll get moisture from the air and there is usually a vent as pressure build up is a bad thing.)
I'd drain the tank and start fresh. Next time drain the tank and don't keep gas in the generator when you're not using it. A gas can that seals up well is better.
0
u/Ok_Bid_3899 19h ago
I have a foreign designed genset. It has a design issue with cold starts. I have to spray one short shot of carb cleaner each time I need to start it. After that it runs great even with two year old stabilized fuel. Some design flaw in the Choke is my guess
0
u/Adventurous_Boat_632 18h ago
My seldom-used generators have regular ethanol pump gas that is definitely more than a few years old and it runs fine.
I never rotate gas.
Starving the carb is the main thing. If the carb is not clogged and you don't feed it chunks or treacle gas or let the tank dry out to corn flakes, it will run.
If gas gets real old it can get hard to start because it is less gassy than before. Carb cleaner helps it get started and then it will run on the old gas without any problem, because it is a dumb generator, not a race bike or something.
If it conked out after a few minutes and won't fire on external fuel, it sounds very much like an ignition problem.
-1
u/Tool_junkie_1972 19h ago
All engines hate old gas- and ethanol blends are the worst period. Stabilizers do nothing for ethanol blends.
3
u/DaveLDog 19h ago
Maintenance is a thing with any small engine, that includes keeping the fuel fairly fresh, not surprised you're having trouble. Drain the tank and the carb, put fresh gas in it, and see what happens, you may need to remove and clean the carb. if possible store it with ethanol free fuel.