Just for grins, if you found yourself is a situation where you needed gas, but the only available was a 5 gallon blitz can that had been sitting, untreated, for MANY years, how would you "freshen" it up for use in say...a generator.

Filter it?  Any way better than another??

I've heard somewhere about running a bubble line of ...propane?... through it to increase reliable starting?

Put in in glass to see the water content that settles?

Other?

add water to it.  shake. let it separate.

Assuming I had access to it, I'd add PRI G to it as well as some acetone. If it was well diluted with fresh gas it'll probably be ok.

If it's turning into varnish, I would not even bother though. Use it to light a campfire.

Gasoline, stored in an airtight container, will last for quite a few years, contrary to popular opinion.

Find a Diesel engine and use other sources

Coffee filters, it'll take time but they filter well. Place inside a funnel, use a couple pencils or similar between the filter and funnel  to give better flow.

That would be the ethanol. It absorbs water from the air, and tends to eat away fuel lines.

This is the big Caveat Emptor!  
Risk versus reward.

Gasahol, tho, stored in a vehicle fuel tank, will last for 90 days and then become an acidic sludge eating away at any gasket, o-ring, and steel OR aluminum with all the water it carries, much less the condensation constantly getting introduced in cool/warm spring and fall temperature swings.

None of the local small engine guys will warranty repair yard equipment and anybody who uses it is getting wise to the no alcohol premium being offered. NONETHELESS the public still comes in with requests about what is the best thing to do and now all I say is drain it and start with fresh, good luck, you are going to have problems. Usually some older car sitting for two years due to it being misdiagnosed and ignored while the owner goes out to buy something nicer on a whim. Basically throwing away a 6k vehicle instead of selling it for whatever they can get.

Farmers were hated for doing that with 55 Chevies and old Hudsons, before that, 33 Fords. "Economical cost of repairs" is the excuse but most of the time the repairs accurately diagnosed are dirt cheap. The owners just won't find out.

It's the time of year - heavy freeze yesterday - where I drain and run dry the yard machinery, fog the motor, and enjoy knowing it will start on the first couple of pulls with fresh mix or fuel in the spring. Been there, done that, bought the carb rebuild that almost cost as much as the weed trimmer.

Don't be that guy, drain the fuel first, run it dry. If you find old fuel now? 50 different additives and worse yet, alcohol, up to 18% tested in our area by the fleet buyers.

This is why most up to date preppers are not using gasoline for their gensets, they use propane. It stays good, it's not contaminated with feel good additives, it stores for decades, it doesn't deteriorate. Propane is the answer you are really looking for. Not gasoline. Ask yourself, what do people who live long distance from major urban centers used for fuel for their homes? Petroleum? Coal? Nope. Propane.

The first company who makes a propane mower with refillable canisters will get money from me, same for a chain saw, weed trimmer, etc. Lithium batteries are massively expensive in comparison for their short lives and heavy user weight. It's almost as if there were some kind of conspiracy or something . . . and yet the infrastructure is there for barbecue grilles.

So you're saying the ol Minneapolis-Moline tractors with the integrated LP tank in front of the steering wheel was ahead of its time?

Gasoline with alcohol will last way longer than 90 days. I do it all the time and hAve for the past 15 years. I have 3 Jerry cans in the shop that are filled with ethanol gas. I usually rotate the gas every two years. It's as good the day I pour it into the truck as the day I pumped it.

I use ethanol in every small engine I own. My ATVs sit over the summer for months with the fuel in them. I usually use them the most in the fall, winter, and spring. No issues with fuel going bad.

My riding mower sits all winter (Dec-Apr) with ethanol fuel in it. Starts up just fine in the spring.  Same with my gas weedeater.

My two chainsaws sit with ethanol fuel in them for up to 6 months between uses. Haven't cleaned the carbs yet and they are a few years old now.

The biggest issue with small engines is the gravity filtration system. Since its gravity fed, you can't have a very effective filter because you don't have pressure forcing the fuel through a fine filter. Small engine filters let a lot of grit through and eventually that grit has to be cleaned out of the carb. Carbs have very small jet passages that don't take much grit to eventually cause running issues. Carbs, by virtue of their design, inherently suck. That's why small engines are slowly going to fuel injection. That said, there will always be a place for carbs in things like chainsaws, weedeaters, and small push mowers. However, battery technology is improving by leaps and bounds so if you are just a homeowner who needs to weedeat for 15 mins or cuts an occasional branch up, it would definitely be worth looking into battery powered tools. I doubt I'll ever replace my chainsaws with electric but when my Stihl weedeater dies (even with evil ethanol it refuses to) I plan to replace it with a battery powered one.

Now, all fuel, give enough time and regardless if there is ethanol in the fuel or not, WILL go bad. The speed of its deterioration depends on how much exposure to air that the fuel gets. So, for infrequently used things like generators, I'd agree that propane is an ideal fuel.

The fuel people use for their homes depends on location. Propane is common in many areas. In other areas, it's not common. Go to the north east and you'll find most people using fuel oil to heat their homes.  In extreme cold climates, propane is not ideal due to its need to vaporize and as temps drop to extreme lows, propane eventually stops flowing. So, for areas like that, fuel oil is a commonly used fuel.

Propane is often cheaper than gasoline UNLESS you are using 20lb tanks filled at a local place. Or, even worse, those tank exchange places. Get yourself a fill kit and fill your 20lb and larger bottles from your home tank using the wet leg of your tank. You can then fill your 1lb bottles from a 20lb tank with the right adapter. Also, you can now buy specifically refillable 1 lb bottles that are much better quality than the disposable propane bottles.

LOL

lol

Best way to take old gas and make it burn in a car is to mix it 50/50 with good gas.
Plain and simple.
This way the car will burn it without problems other than maybe some spark knocking.

Hey old friend.

Can you expound upon this? I'm curious what properties of ethanol cause the aforementioned "gunk"...

But the internet said it's true........

"Ethanol is bad so I'm gonna add alcohol to my gas (in the form of Seafoam) to preserve it..."

Yes.  I had close to 40 gallons of bad gas that I had trusted to Stabil.  I came here and asked the same question.  Pri-G fixed it and I ran the gas in my daily driver.

Exactly.  If it fucks up your Honda quad, Generac generator, Poulan chainsaw, Yamaha Rhino or Raptor, you will be replacing the fuel lines, petcock, and fully disassembling the carb to get the nasty shit out of the micro orifices of the tubes inside the carb.  There is no other way to fix it unless you are extremely lucky.

I mention those items by name, because, I had to do that labor myself. I run any engine I am storing until it is empty, lesson learned.

I have 5 year old gas in the wife's Honda quad with Pri-G in it.  Anyone want to take bets whether I can throw a battery in that quad and start it up?

Oddly enough I've simply never had ethanol screw up anything... It's bailed me out a few times when I got water in the fuel tank of xyz engine left sitting outside... it's cleaned up nasty old fuel systems... The only way it can screw things up is if you use it in non-compatible fuel systems (shame on you) or you run it in a dirty or varnished fuel system and don't clean out the crap the ethanol breaks free before running the engine (once again shame on you).

"micro orifices of the tubes" isn't part of any carb I've ever worked on... did you mean jets, ports, and passages?

I know that seems dickish of me but you can't come in here saying you know things by name bc you had to work on them and then not know the name of the parts. It calls into question your entire claim.

I'm not sure you can find it anymore (damn EPA) but Toluene would kick it back into life. I used to go to Sherwin Williams and buy it by the gallon. was a paint thinner or cleaner I believe. I'd toss it in the tank with some 93 octane as poor mans race gas! lol

I forgot the ratio but I want to say with 3 or 4 gallons of 93 and a gallon of toluene it was 104ish.

xylene was another that worked in the same regard but not as effective.

I want to say during the real turbo era of formula 1 (80's) they used 100% toluene as fuel. they were pushing something crazy like 1500bhp from 1.5L v6's for their qualifying runs.

@wildearp - how old was the gas?  I thought stabil was suppose to preserve gas for up to two years.

how about adding some calcium carbide, converts the water and adds volatile acetylene, you would need to filter well.

Having seen how Calcium Carbide reacts with water, I don’t want to volunteer to mix it with gas.

I use Calcium Carbide in an old miners lantern to blacken my sights during competition. I wonder what that kind of soot would do to a modern automobile?

just throwing it out there ymmv

Right at 2 years.  Generator and both dirt bikes were fucked up with red colored bad gas.  Put Pri-G in it and it ran fine afterward.

Others here, on this board, will tell you that gas won't go bad at all with no additive.

It won't, as long as it is stored in a vessel that maintains vapor pressure on the gas preventing evaporation of the more volatile compounds and preventing moisture/contamination intrusion.

Exactly.

Why do some so strongly resist this reality?

because they never studied physics/chemistry?

And here you go. Interesting. Might be a future purchase.

Interesting...

Quote---

"five times more efficient than traditional fuels, resulting in less fuel being used"

Really?

Propane has been used -indoors- in internal combustion engine for what, close to a century?  Floor cleaners, fork lifts [have one], man lifts,  other equipment that benefits from propane's excellent combustion products, mostly CO2 and H2O. With very little CO.

This use of propane cylinders may be quite useful for certain applications needing easy starting and portability.

15 HP boat motors, not so sure.

Cost of a 1 pound cylinder of propane containing about 22,000 BTU of 'work', vs. 1 pound of gasoline w/ same BTU's?  $3 vs. 40 cents?

Portability, propane needs a heavy steel pressure vessel rated ~400 psi. Gasoline, well a Gatoraid bottle will do in a pinch.

Analyze...

If you to separate water or debris from fuel there is this thing called Mr Funnel. It also goes by the name Flotool.
http://www.mrfunnel.com/Mr._Funnel/Home.html

If can save aggravation and time when trying to separate water from fuel.

AND WE HAVE A WINNER

We have lots of 5 gal cans of old alcohol gas of varying ages.

One thing I think I'll try, maybe in the Champion genny, is to add some DOT 4 brake fluid to the gas, just about 1 oz per gallon and see what happens.

This is somewhat of an OT, but i bought a gasoline powered lawn mower at my local Home Depot, used it to mow the grass only once; the 2nd time it just would not start, did a bit of research, the alcohol in the automotive gasoline screwed it up. Now if I had a gennie, i would probably go to the nearest airport and get some Av gas.

From your analysis, the Home Depot must be lined with used and broken lawnmowers from folks using regular gas.

The airport must be terribly busy from folks who don't.

This seems like there's an opportunity here somewhere?

Hey indeed..

There are two problems with old gas, polymerization from water and air contamination, and loss of light compounds through evaporation.
both can be cured by proper storage in air tight containers.
gum can be filtered out, volitiles  can be replaced with toluene, xylene, or propane to restore octane.
storing premium gas in an air tight container will solve the issues.

As stated above. I pour all my leftover boat gas thru one before I run it in the truck. It's amazing what that filter catches.

Actually, it doesn't even have to be premium.

We prefer to store mid-range gas because it has lower octane and presumably has less of the lighter fractions that would tend to evaporate more quickly when exposed to atmospheric pressure. Maybe for this very reason we should store high octane.

Unless we've contaminated our fuel [we're careful to maintain good handling practices],  when we go to use it we never need to filter it.

Works for us without any other intervention ---aside from, as you say, storing hermetically sealed in a good functional container.

No need for additives after storing many years.

Especially modern alcohol ethanol enriched gas that seems to have no detectible ----in practice, gum or varnish. It actually cleans our fuel systems of many different engines.

This said, if you are running a 1950's or 60's weed wacker, mower, ambulance, etc., then there could be compatibility issues with hoses and seals and issues that need to be corrected for correct operation. That isn't our situation.

We haven't detected elastomer issues in 1990 and up year model vehicles having had gas stored in them for as much as 5 years between starts.  A Ford truck stored indoors, with CA fuel, started on 2 different occasions after an approx. 5 year interval between starts.

On the first twist of the key both times.

EXPY DOESN'T DRIVE 50 MILES TO BUY non-ALCOHOL GAS.

The biggest issue we have at our present location is particulates [silicon 'dust' ---very fine sand] that is visible as reflective 'stuff' in the bottom of our Honda gennys' tanks ---that's how we learned of this and the resolution, after we had a lot of carb clogging issues.

The 'particulate clogging' issue has NOTHING to do with the fuel! [Altho I and likely anyone else would initially attribute the problem to the fuel until they had the motivation and took the time to do an analysis, that very few would do]

The particles enter the carb and there is no solvent or repair technique known to man [other than a plasma cleaning in high vacuum -maybe, that will remove the particulates once "congealed" in one of the orifices.

It takes removing the carb [how many times have I done it before I figured it out]

And mechanically cleaning the jets, and not the one at the bottom.

I've done extensive analysis of this issue a few years ago and shared the information and techniques in several topics here.

Including a complete detailed analysis of the ports, seals and jets under magnification of the Honda carb in my lab. Learned a lot.

The end solution was to install good quality inline filters in the Honda 2000ie's [not particularly easy due to space issues] and no more problems.

I've got 2 Honda 2000's that haven't been started in over a year and a half, and I'm confident they'll start in about 25 pulls of the cord.

25 pulls seems to be the number required to get the crankcase pressure differential operated fuel pump primed and carb filled.

If they run without needing choke, then the carb is likely good to go.

Maybe I'll start one I have here, today, to verify...

Since the Champion remote start genny was recommended here a couple years ago, and installed, my SO hasn't needed to run the Hondas.

The Champion is left outside the container, with no cover except in the winter, in rain and snow, and always [so far] starts.

Rain on the gas cap ---OMG  

Alcohol laced gas. LOLOL!

No security blankie snake oil/mineral spirits to sooth our feelz...

And instill mis-guided confidence in our equipment.

The only starting issue common to all our engines is when they get around 20 degrees F.

Then, we [used to] take the Honda inside the container to start in warmer air.

The physical temp of the engine isn't a significant factor if warm air can be introduced to the intake.

Since it's inconvenient to take the 100# Champion into the container to start, I added an opening [covered by an elastomeric 'flap']  to the air intake for propane injection from a torch.

Works fine when it's cold.

Where did the 'junk' your filter catches...

Come from...

hello bud.  I hope you are faring well.

I've used gas that was stored in a non-air tight container that was 2 years o;d with no issues.

About 10% had evaporated so I know the container had been exposed to air and humidity.