How Long Until Mixed Gas Goes Bad?

I think it lasts longer, afaik. I've used 3, maybe 4 month old saw gas without noticeable problems. Not that I would contradict Madsens, they know their stuff. Just saying.
 
If it's real hot outside and my gas can is blown up like a balloon I find my mix goes stale really fast within a week or so.
 
I don't use nearly as much as most of you .However about after a month I dump it in the lawnmower or old tractor just to be safe .
 
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From Madsen's Site

Our Advice
•Use E10 supreme grade 91 octane fuel.
•When you purchase fuel, don't buy it from a filling station that permits different blends to be dispensed from the same hose.
•Keep the carb adjusted properly. Get a tachometer and use it often.
•Since reformulated fuel causes the engine to run leaner, enrichen the carburetor when running it. This is especially important on the high speed adjustment.
•Keep the engine's cooling system in good working order. Make sure the air passages in the starter housing are not blocked with wood chips. Also see that all the cylinder's cooling fins and air passages are clean.
•Use either Stihl or Husky brand mix oil. Avoid multi-purpose two-cycle lubricants even if they are sold by a big oil company with a good reputation.
•Mix gas and oil at a 50:1 ratio for both Stihl and Husky pro saws. Mix accurately and don't add extra oil.
•Mix fuel in small quantities. Fill the container halfway with raw fuel. Add all the mix oil. Fill the container the rest of the way with fuel. Agitate if possible.
•Don't use mixed fuel if it is over six weeks old. Tests show that as the mix ages, the oil is less likely to stay suspended in the fuel, even if agitated.
•Once fuel is mixed, use all the fuel in a container before adding any more. No portion of the fuel should be over six weeks old.
 
100 octane racing fuel's much better in my recent experience, in every saw.

7 bucks a gallon and worth it.

Jomo
 
Well that's point of debate .It may be better for a highly souped up saw but on a stocker ,highly debatable .---but so is the oil mix ratio for that matter ---:D
 
Having higher octane at the pumps here, I regularly buy 100 octane for my saws. Most saws seem to run better with it, other smaller saws, like the 020 and probably MS200, seem to run better with the 90 octane range.
 
Having higher octane at the pumps here, I regularly buy 100 octane for my saws. Most saws seem to run better with it, other smaller saws, like the 020 and probably MS200, seem to run better with the 90 octane range.

Jay, I would really be interested to know what kind of fuel you buy. My father in law in New Zealand buys 100 octane at the pumps as premium. It turns out that his gas is the same as my gas, the difference is that New Zealand does not take the average of the octane numbers, just the highest.

Japan probably gets good gas though, seems like a high performance culture. Or maybe i watch too many t.v. shows!:)

I was once hollered at for buying premium gas for my bulk tanks at home. They said that nothing i had on the place required premium gas. My stuff in MY opinion runs better on premium. It would be hard to prove the benefit to a naysayer though.
 
I store in 1 gal steel containers that seal tight and have had no noticeable degrade in 6-8 months time. YMMV

Where as if it sets in the saw's tank for a few weeks it smells stale and I dump it.
 
AV gas burns slower so in theory it would burn cooler . I'm not so certain it would produce any more power than standard 91-92 octane rated HI-test pump gas .The only reason I even bother with Hi test is because I have a hand full of modified saws .
 
Jim, we use the RON rating here, and apparently New Zealand does as well. It says that some New Zealand stations will have 98 RON available for premium, which is quite high octane, I believe. I was interested and called around to a few gas companies to see what they had to say about their gas octane. The brand I regularly buy from tells me it's 100 octane RON. Probably that the car manufacturing industry is so large and powerful here, has something to do with the good gas available.
 
When I first tried the racing fuel, that is dispensed from its own pump?

I went inside and asked to see the racing fuel's octane certificate from the refiner, which he produced showing the octane at a 100 minimum, from the refinery.

Dudes with big bucks in their high compression toys love the stuff, just like my saws do!

Prior to usin this fuel and running 91? Had to clean carbs full of jelly like stuff on a regular basis to run well.

Haven't needed to do that in over a year now!

Jomo
 
Ime around here gas lasts a good long time. Six months easy. I never have mix sitting to long but I do have a vehicle or two that easily over winter about 4-5 months with no fuel issues. No additives ever.
 
All gas in Hong Kong is 98 RON. I think that's equivalent to 93 in the USA rating system. I have left has in saws for months at a time here, and so fat no issues. I'm not suggesting that anyone else do that though.

Justin, like you my truck over winters without fuel additives. I have noticed that my mileage isn't quite as good on that tank of old fuel in the spring. Seems to run OK though.
 
http://www.madsens1.com/saw_fuelmix.htm

I was just going to post a question about carbs going out of adjustment on 2 saws. I thought it must be the gas. I answered my own question on looking for an answer to yours. Pretty good info.

That was GREAT post. However, they REALLY should put the date they posted this info. If this was from 10 years ago, how would we know how valid it is...

Still, it's a great read.

Michael
 
It's my assumption that perhaps with Californias' stricter emission laws and the use of special blend "reformulated gasoline" that the results could be different .According to what information I have this is not the gasoline most of us use.--unless you live in California ---
 
The gas pumps here won't fill plastic containers any longer. They passed a law a couple years back, some speculation about static electricity or something resulting from plastic causing a container to blow up. Through the eons of time and one speculated upon incident necessitated a law. Metal gas cans flew off the shelves throughout the whole country. Could there have been some politicians making money surrounding that? I sometimes transfer to the plastic, but it makes me wonder if there really is a good side, like storing in metal creates longer lasting gas? I also wonder if larger quantities will last longer before going bad, than lesser in a container? So many questions to complicate life....
 
Commersial fuel is very different in different regions and brands.
Very hard to say anything general as they vary quite a bit in quality and rarely are up to promises when you look a bit closer.
 
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