How long will mixed (2 Cycle) Gas keep?

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I know there's already another thread about regular gas. I was wondering the same thing about mixed gas. I have a Stihl trimmer. It's about 10+ years old (received from my father), but works as good as new. 1 gallon of mixed gas will last me 2+ years. I've been using the Stihl 2 cycle oil. Is it OK to use 2-yr old gas in this trimmer? I always shake it real well before pouring in. Or, should I only make a half batch: half bottle oil/half gallon gas? I'm on my last tank now, so I'm about ready to mix up another batch. Thanks in advance.
 
I use a Tanaka straight shaft string trimmer I inherited. I didn't get any instructions so I tried a 50 to 1 mixture with fresh gas. I only mix a quart or less of fuel at a time for the trimmer. I have several brands of two cycle oil for air cooled engines. Bought the oil for my 125cc
DKW/Sachs motorcycles. The cycles use a 25 to 1 mixture. I think the fresh gas is a benefit for both. Curley
 
I should have added that you could/should use a stabilizer additive if you want to keep the gas for more than a year. I haven't spent the change for the additive because I use the fuel before it gets old.
 
Some 2 cycle oils contain a fuel stabilizer. I know that Lawn Boy oil contain it. I usually use up a gallon in one season.

If there's no stablizer, I would use it up within 6 months to be safe or even use it up slowly in some 4 stroke engines. Otherwise I would try to use it up within about a year.
 
Thanks. That's what I thought. I'll only mix 1/2 gal -- and try to use it more often:) My local Stihl retailer H/W store closed. I'll have to find a new one. The trimmer is excellent. The small shop we bought it from stated the "motor was built in Germany. The only way to kill it, is to run straight gas through it."
 
I wouldn't use it for more than a couple months if the fuel had ethanol in it. I don't know about your area, but in MN we have a mandated ethanol blend in all gas with the exception of special pumps that are supposed to be used for offroad and classic vehicles. The ethanol is fine to use as long as it is fresh.
 
Stihl recommends a maximum storage period of 3 months for mixed fuel, minimum 89 octane. This info comes right out of the Stihl FS45 lawn trimmer owner's manual.
 
Thanks for the info. I was on their website also -- but didn't see the time period. I noticed the 89 octane -- which I hadn't been doing. I also read their oil has stabilizer in it. I'll be lucky to go through 1 tank in 3 months. Now I have a new dilemma.
 
My Weedeater trimmer and Polan chain saw won't idle on old mix, and the saw is low on power. Any mix over 6-8 months old gets dumped in the riding mower. Hmm, maybe thats why the plug gets fouled every 3-4 years.
 
same here my timmer wont run on the gas I mixed in the last year. I might try that fuel stable stuff. after all with gas prices now cant dump it now its liquid gold.
 
quote:

Originally posted by Oldmoparguy1:
My Weedeater trimmer and Polan chain saw won't idle on old mix, and the saw is low on power. Any mix over 6-8 months old gets dumped in the riding mower. Hmm, maybe thats why the plug gets fouled every 3-4 years.



Noticed you used the word "dump".

How do ya'll dispose of old two cycle, oil-mixed gasoline? I have about one gallon leftover.
 
quote:

Originally posted by Triple_Se7en:

quote:

Originally posted by Oldmoparguy1:
My Weedeater trimmer and Polan chain saw won't idle on old mix, and the saw is low on power. Any mix over 6-8 months old gets dumped in the riding mower. Hmm, maybe thats why the plug gets fouled every 3-4 years.



Noticed you used the word "dump".

How do ya'll dispose of old two cycle, oil-mixed gasoline? I have about one gallon leftover.


i usually mix old 2cycle from my boat or trimmer with a little fresh and use it in the tractor or push mower. it works ok. there is usually a hazardous waste day at least once a year in my area that one can take oil/gas/thinner etc..
www.earth911.org has listings for many states.
 
Maybe one of you will remember this, or maybe my mind is playing tricks on me, but I seem to remember reading something about FP60 being able to "rejuvenate" gas that has sat for awhile without any stabilizer.

Does that ring a bell with anyone? If so, do you remember if any particular time period was mentioned as being the limit?
 
quote:

Originally posted by Dark Jedi:
same here my timmer wont run on the gas I mixed in the last year. I might try that fuel stable stuff. after all with gas prices now cant dump it now its liquid gold.

"dump" it into a car/truck with a near full tank.
thats how i use up 2 stroke mix at end of season.
 
^^ Yep. I was at my local Stihl dealer. He stated the gas (using their oil) could last 2 years -- but he didn't really recommend it. I had < 1/2 gal left, so I dumped it in the van. I mixed a fresh batch, and changed to the E3 Spark Plug. It started better, and ran a lot smoother now. The old spark plug didn't look too bad.
 
I should add that I start with 93 octane in all my equipment. I figure after a couple months it's down to 89 and so forth.

BTW: I only use stabil in the tractor all other equipment gets ran dry and drained.
 
quote:

Originally posted by kc8adu:

quote:

Originally posted by Dark Jedi:
same here my timmer wont run on the gas I mixed in the last year. I might try that fuel stable stuff. after all with gas prices now cant dump it now its liquid gold.

"dump" it into a car/truck with a near full tank.
thats how i use up 2 stroke mix at end of season.


Same here. once you add it to even a half tank of gas,the dilution rate is extremely low. If you have an older car, you probably burn more engine oil than is going to be in this mix. I just put it in at the end of the season and that way I KNOW my gas is fresh next season.
 
my trimmer wouldnt even start with one year old gas/mix, put fresh in and it fired right up. i hae to mix small batches for that very reason. i knew about the octane thing but forgot, i need to remember that next time.
 
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