How old is old gas?

[The Haymaker]

I have never gone to the trouble of running something dry to prevent problems. I wouldn't think you would want to fuss with your generator to get it started after running it dry. When you need it, you need it right away. Properly stabilized gas and a full tank will easily last 12 months without causing problems. This is my experience in my part of the country. It could be different due to environmental factors. We do have high humidity at times though.

I just finished rebuilding the Kehin carb in a 2006 dirtbike that is stored inside, heated, and never has the gas (with Stabil) turned off. All the rubber was like cardboard, to the point the rubber tip of the float needle was separated and stuck in its bore.

You'll find things start better if the gas has been off and bowl drained. There is no stale gas or condensate. Turn the gas on, wait two seconds, and light.

 

[nikdfish]

It should be good for a year with Stabil. Start your generator once a month and to stop it shut off the gas. That way the carburetor will be empty preventing oxidation.

Same thing here. I usually keep properly "Stabiled" gas for up to 12/18 months. It gets used in the mowers or truck if not needed for the generator before that. I try to have 40+ gallons or so on hand (in a gas storage building away from the house) & rotate stock to use & replace the oldest first. If I don't use up he generator's tank contents before 6 months or so, I'll drain it & put it in the truck. I generally don't fill the tank unless it looks like an extended run is in the offing. I leave a partial fill in there for the monthly generator run.

Running a generator on a monthly schedule, with some kind of load (I use 2 1500 Watt milk house heaters) is good for keeping the field coils "energized". A generator that has not been used for an extended period can become unable to produce power. There are fixes, but periodic use is definitely the preferred approach.

Nick

 

[boxygen]

I have a generac 5500 that is 2-3 years old. It doesnt have 10 hours on it. I dont think I've run 2 tanks of gas through it. I try to pull it out and start it every couple months but I cant say it that I remember consistently. I always have marine stabil in the fuel. We lost power on Monday so I pulled it out and it fired right up and ran fine. I do remember that when I topped it off last time with fresh fuel it did run a little smoother. For whatever reason I dont worry about my Generator but I always drain my Snowmobile. I know I have run 1 year old plus stabilized gas in my chainsaw too. I think they run better on fresh fuel but you arent doing any harm running 1-2 year old gas as long as it has Marine Stabil in it.

 

[sld]

I just finished rebuilding the Kehin carb in a 2006 dirtbike that is stored inside, heated, and never has the gas (with Stabil) turned off. All the rubber was like cardboard, to the point the rubber tip of the float needle was separated and stuck in its bore.

You'll find things start better if the gas has been off and bowl drained. There is no stale gas or condensate. Turn the gas on, wait two seconds, and light.

I see your point, but do you really think your fuel systems get completely empty? I guess with the equipment I use it has never caused a problem. The typical stuff like leaf blower, string trimmer, chain saw, push mower, ztr and even the boat. My boat hasn't gotten much use the last 2 years but i never ran it dry.

Not arguing the fact, just my experience that I have never done it.

 

[ultrarunner]

I've noticed a lot of small power equipment like mowers now have fuel shut-off valves just ahead of the carburetor...

I know my Stihl shop said to run the saw dry if I wasn't going to use it for 30 days...

 

[two4spooky]

We have been doing this for the last 5 or 6 years, luckily never needed it until April 27th of this year. I keep 6-7 of the 5 and 6 gallon cans(a couple metal, most plastic) in an old insulated dog house away from our house. The metal cans work better, plastic will lose about 1/5 of the volume in a year. I always filled the cans each summer and burned the old in my truck. Buy the gas in the summer, you may have trouble with vapor lock with winter gas if your sudden need arises when its 90 degrees. I mixed double dosage of regular Stabil for each can. The old gas will have a much lower MPG or higher GPH usage after storage. I use 1 red bottle of STP gas treatment per gas can when using the old gas and this helps. Octane booster will work in a pinch also but cost more. On the 27th we lost power around 5 am from the first line of storms(wind). The 15,000kw Generac v-twin ran almost continusly for about 135 hours and used if I remember correctly about 85 or so gallons of gas. I spent about $250 on the third day filling gas cans at $4+ per gallon. I have not filled the cans this year becuase of cash spent on gasoline, I am looking for a natural gas conversion. The NG conversion kit for the generator looks to be around $400 plus pluming the NG lines outside the house. If you have NG or LPG available you might want to consider the alternative. Still I was very thankful to be fortunate enough to still have a house and the gasoline generator to run it after the storms.

 

[two4spooky]

Forgot to say, gas was only kept for about 12 months at a time until used. That seems to be about the limit, give or take, for me.

 

[MillWeld]

I have a 10 HP Generac which I start once a month. Lately I bet I have used more gas doing that than using the generator. For years I have just topped it off adding to the gas already there (no Stabil) and I'm surprised it always starts after a few pulls so I am not doing anything different.
I got it because we used to lose power regularly but now I occasionally power a tool in a remote location.
Bob

 

[ultrarunner]

Dusted off the old Model A today and drove it to work... had not been started since last September... battery tenders are great...

Anyway, started right up and no issues.

From my understanding, most of the problems with new fuels are they deteriorate just about anything that isn't metal...

There may very well come a day when the old Model A's are the only cars still on the road... there isn't a single piece of rubber anywhere in the fuel system... steel, brass and cast iron only and no fuel pump!

It had been so long, I had forgotten how much fun it is...

 

[Gary Fowler]

Has anyone noticed the owner's manual saying not to use ethanol gas in any formulation for 2 cycle motors. I was just perusing my new weed eater manual for the correct size string and noticed that it said not to use any ethanol blend gasoline in the 2 cycle engine. Luckily for me, there are several stations that sell pure gasoline close by. They seem to be getting more and more popular as on a recent trip, I saw a Shell station in Wyoming also advertising "pure gasoline." My Poulan manual said that the oil doesnt mix right in alcohol mixture gasoline. After several carb rebuilds, I now run nothing but the pure gasoline in all my small engines and use Stabil also.

 

[ultrarunner]

Has anyone noticed the owner's manual saying not to use ethanol gas in any formulation for 2 cycle motors. I was just perusing my new weed eater manual for the correct size string and noticed that it said not to use any ethanol blend gasoline in the 2 cycle engine. Luckily for me, there are several stations that sell pure gasoline close by. They seem to be getting more and more popular as on a recent trip, I saw a Shell station in Wyoming also advertising "pure gasoline." My Poulan manual said that the oil doesnt mix right in alcohol mixture gasoline. After several carb rebuilds, I now run nothing but the pure gasoline in all my small engines and use Stabil also.

My dealer said the same thing... the only alternative here is to buy premixed quarts at $5 each...

 

[mjw357]

Sounds like you don't use it very often, why keep any gas in it at all? Draining and refilling every few months sounds like a lot of messing around for nothing. If you don't expect to use it any time soon, just run it dry and store it.

 

[me0418840987]

My 84 GMC C60 sits for months at a time during winter, never had a single problem with old gas, ethanol blend 10%. None of the other vehicles sit long enough to have any problems at all. Both of the salvage yards I go to take the fuel from junk cars and put it in a tank. I know that the owner of one runs it in the 2006 Chevy pickup he drives every day. He has two filters in the system, and just makes sure that it is coming out of the nozzle clear and not orange. The other blends it with the drain oil for heating the shop.

 

[rkeith]

I'm not sure if this is a state or federal thing but to answer the question about old gas...
Gas can't be bought from the distributor if it's older that 90 days. To better explain this, the mom-n-pop gas station that sells cheap simply buys the gas that is 30-90 days old; thus, this is cheaper than the "new gas". Gas has a "sell by" date on it just like food products do! May people may not know this but the "new gas" gives you better gas mileage because it hasn't began to breakdown yet at the molecular level.

 

[whiskywizard]

The gas "canary" for me is a pair of Honda 1000 inverter generators. They seem to need the freshest of fuel.

I often add stabilizer to my 5 gal jugs, but not always. Even after a year, the unstabilized fuel is fine for car, truck, sleds, chainsaws, trimmer, ATVs, etc, etc. But not those Hondas. With fresh fuel, they start first pull. As fuel passes about 3 mo, I can expect 5-6 pulls. if the fuel in them goes by approx 6 mo, they simply won't start. Dump it out, drain the carb, put in fresh fuel, 2 pulls.

 

[whiskywizard]

and just makes sure that it is coming out of the nozzle clear and not orange.

Yeah - so true. When fuel does go off, it's very easy to see and smell. There's no mistaking it.

 

[k0ua]

The gas "canary" for me is a pair of Honda 1000 inverter generators. They seem to need the freshest of fuel.

I often add stabilizer to my 5 gal jugs, but not always. Even after a year, the unstabilized fuel is fine for car, truck, sleds, chainsaws, trimmer, ATVs, etc, etc. But not those Hondas. With fresh fuel, they start first pull. As fuel passes about 3 mo, I can expect 5-6 pulls. if the fuel in them goes by approx 6 mo, they simply won't start. Dump it out, drain the carb, put in fresh fuel, 2 pulls.

Thats interesting, I have a Troy-Bilt 4 cycle weedeater, that is my "canary" It refused to run on old gas, (will start but wont accelerate) yet that same old gas will run my JD lawn tractor just fine.

James K0UA

 

[The Haymaker]

I'm not sure if this is a state or federal thing but to answer the question about old gas...
Gas can't be bought from the distributor if it's older that 90 days. To better explain this, the mom-n-pop gas station that sells cheap simply buys the gas that is 30-90 days old; thus, this is cheaper than the "new gas". Gas has a "sell by" date on it just like food products do! May people may not know this but the "new gas" gives you better gas mileage because it hasn't began to breakdown yet at the molecular level.

Logistically, that'd be a hard thing to do. Here in Maine, majority of the gas comes from two different bulk sites. Doesn't matter if you are buying Irving, Sunoco, whatever, IT ALL COMES FROM THE SAME SHIP. So, it'd be impossible to buy "expired" gas.

 

[whiskywizard]

I'm not sure if this is a state or federal thing but to answer the question about old gas...
Gas can't be bought from the distributor if it's older that 90 days. To better explain this, the mom-n-pop gas station that sells cheap simply buys the gas that is 30-90 days old; thus, this is cheaper than the "new gas". Gas has a "sell by" date on it just like food products do! May people may not know this but the "new gas" gives you better gas mileage because it hasn't began to breakdown yet at the molecular level.

Where did that "old" gas sit while it aged? And how does one track the old stuff as it approaches 90 days?