Old Gas

[CarlH 436]

How long does current unleaded gas remain useable? I am getting my Oliver (bigger) tractor running after 3 - 4 years of sitting and am cranking and have good spark. It will run (briefly) from a shot of ether. I've drained a little gas from the bottom of the tank and cleaned out the sediment bowl and carb. The gas in the sediment bowl is fairly clear and doesn't smell terribly bad. I've got about 20 gallons in the tank, any experience or ideas? Thanks.

[Ketchamized 2]

Carl, Did some research on this subject a while ago. Most experts say that gas has 6-18 months shelf life without gas stabilizer. It depends on the climate the gas was stored in. Some experts say just a month. But I know personally for a fact that you can use gas after it's been stored for a year. (I've done that before, although I don't really recommend it) Also, it depends on how much condensation got in the gas over the years. Gas generally is at its best the first 2 months, then the quality goes down, but still useable. At this point, I would think that the concern is sediment getting into your carb and engine. It may be a good idea to look into your tank with a flashlight and see how badly gone it is. Gas today gets old much faster than it did 20+ years ago. Fuel stabilizers only work when you put it in when it's fresh. Once it's old, there's nothing you can do... Except hope it'll fire. Here are a couple articles that may interest you: http://www.straightdope.com/columns/060825.html http://www.alpharubicon.com/altenergy/gaslifepal.htm

[CarlH 436]

I am not so concerned about sediment. I replaced the screen in the sediment bowl and the inline filter between the sediment bowl and carb and cleaned everything thoroughly. There was relatively little water in the bottom of the the tank probably because it was pretty full and treated with Stabil when it was put in the tank. The carb (a Marvel Schebler) is pretty primitive and fairly impervious to crud in the gas because it settles out in the carb bowl also. Thanks for the links.

[Paul_B 0]

First, I'd put in a new set of spark plugs. I've had motors that wouldn't start but had a spark at the tip of the plug. Next, how's your compression? Squirt a touch of oil in each cylinder to help the rings seal which will give you better compression. I've started cars with gas that old, but they don't run well. As soon as I was able to add fresh gas, they ran much better.

[PGL 449]

Have a look at www.priproducts.com they have developed additives for both gasoline and diesel which apparently can even rehabilitate old fuel. Many very respectable users.

[Danny 0]

New fuel problems....I'm straying a little from the topic here but hopefully this advice will help others as it has for me. My otherwise good running Oliver 77 did not run worth a hoot with the new gas that came out. Sputtering, spitting and it seemed the gas would get hot in the carb. and vapor lock. I rebuilt the carb. a few times, tried to shield it lines etc. from any engine heat and finally tried different treatments. Still I couldn't get the darn thing to run right, In discussing this with a neighbor he told me to mix a cup or so of diesel in with the gas. I did so and after a little running the old 77 straightened right out. Now I mix a cup of diesel in every 5 gallons of gas I get. It really does seem to improve the way all my gas engines run. Sorry I strayed from the topic but maybe my advice can help out if anybody has stuff that doesn't like the changing gas. Danny Tabor

[CarlH 436]

I like Paul's spark plug idea. A mechanic friend said that plugs that had gotten wet from unleaded gas could be very hard to fire. The last time I made an attempt to start this tractor, I flooded it badly. I also think I will rig something up to feed fresh gas into the carb. Thanks much.

[goatfarmer 817]

I've got a 68 Pontiac GTO, that I haven't driven on the road in 5 years. It has about 1/4 tank of gas, which I treated with StaBil. Once a year, I clean the garage it's parked in. With a fresh battery, the car has never failed to start. I start the car, pull it out, clean the garage, and back it in again. So far, no problems, FWIW.^

[UCD 14]

quote:

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plugs that had gotten wet from unleaded gas could be very hard to fire.

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That is an Old Wives tale, any plug that is wet from any gas will not fire. Dry the plug with a Lighter or propane torch and reinstall if the plug is good it will fire as any other plug as long as you don't flood it again.

[Ketchamized 2]

Carl, It sounds like it shouldn't be too much of a problem using up that gas since you put gas stabilizer in it. I'd add that additive that PGL suggested, and do what Maynard suggested and dry the plugs. While the plugs are out of the hole, dry-crank the engine and let the flooded gas spit out of the spark plug hole. Then put the dried plugs back in. Put fresh gas in the carb bowl and turn the gas tank back on and fire it up. Good luck, hope it works out well for you.