Does gas really go bad?

[MossRoad]

Did the Wiki thing with gas the other day. Filled my 5 gallon can with regular unleaded at the filling station (BP), took it home, took a 1 gallon clear plastic water jug, put a pint of bottled water in the bottom with red food coloring, dumped in the regular unleaded to about an inch from the top, put on the lid and shook it up real good and sat it down and watched the corn alcohol precipitate out of the gas to the bottom of the jug along with the entrained water. This morning all the corn alcohol is in the bottom with the water and the gas is clear as water. Gonna siphon it off and fill it again and again and again, until I have at least a 5 gallon can for the small engines. Non e-gas is hard to find around here and those stations that have it charge a premium price for it.

You do need to add about 1/2 ounce of acetone to the 'refined' gas to get the octane rating back up. Removing the corn alcohol drpos the octant rating a bit.

Why? :confused3:

 

[5030]

Why? :confused3:

Why what? if you mean the acetone, it increases the octane rating a couple points. Pump regular today is about as good as Mexican Pemex used to be.

I've coagulated a couple carbs from letting e-gas sit before myself. I don't much care to rebuild a carb that is gunked and yes, stale e-gas stinks too and it's corrosive to die cast aluminum.

 

[5030]

Doesn't a lot of pre-mix oil have stabilizer in it?

Stihl pre packaged pre mix does but stabilizer only prevents phase shift which is the tech name for the corn alcohol dropping out of the gasoline and forming a a gunky mess in the bottom of your carb.

 

[MossRoad]

Why what? if you mean the acetone, it increases the octane rating a couple points. Pump regular today is about as good as Mexican Pemex used to be.

I've coagulated a couple carbs from letting e-gas sit before myself. I don't much care to rebuild a carb that is gunked and yes, stale e-gas stinks too and it's corrosive to die cast aluminum.

I mean why are you going through the bother of removing the alcohol from the gas. Do you really have that much trouble with 10% ethanol?

 

[not2old]

I recently started a 1993 Volvo that had gas in it from August of 2017. It started after I put in a battery and cranked for less than five seconds. I ran it for a few days on the 3/4 tank it had and after filling it up noticed no change in how it ran. Years ago, I started a 1974 Husqvarna 2 stroke motorcycle on the first kick after sitting for seven years with a full tank. It never started that easy with fresh gas.

 

[defranks]

I have to assume that Husky was stored with the carburetor empty. If I leave gas in the carbs of any of my two stroke bikes for more than a week or so, they give me grief. I have to drain the float bowls and let fresh fuel refill them. I put petcocks on all my four-stroke engines, too, and let the fuel run out when I'm done for the day. I dump all the fuel from my chainsaws and run the carbs dry, too. I've cleaned a lot of carbs that sat with fuel in them. I once bought a Kawi KZ1300 six-cylinder bike for half what it was worth because it wouldn't start. I pulled the carbs and cleaned them and rode that bike for years.

 

[Gale Hawkins]

Just my own experience... I've never had a fuel problem with "old" gasoline. I only use 87 octane 10% ethanol. I've been using that since the 80's. It's the fuel that's recommended by all of my engine manufacturers, so that's what I use. I've had one (1) fuel line go mushy on a chainsaw. I'm told it was ethanol related, but no one can confirm that. Most of my engines get used regularly, but things like the log splitter can sit for a year or more. Never a fuel problem. Our first tractor was a mid 70s IH2500b with a gas engine. It would sit all winter out on our remote property. I'd check the glass water bowl under the fuel tank and never found water in the tank in the 10 years we owned it.

There's all kinds of stories about old gas, ethanol, etc... I don't doubt people have problems with it. I guess I've just been lucky.

Same here.

 

[shooterdon]

I have been cursed and blessed. Some engines are a nightmare if I let them sit with ethanol gas...others seem fine.

I am too old to keep track, so use Stabil or Seafoam in them all. Seems to help, but maybe not...

 

[fried1765]

Owning a plane makes avgas available to me. 100 octane, 2% TEL. That stuff NEVER goes bad.

auto fuel is bad juju for anything that doesn't have a catalytic convertor. My Model A and Harley do better with Avgas, even my chainsaw likes it (and smells better too) My old sears tractor the grandkids drive when they visit works great.
There's paperwork available for airplane engines to allow the use of autogas, as long as there's no alcohol. At the airport they called it "Mogas" but as far as I know, it's not available anymore.. I do hear that some marine fuelers have it available.

If auto gas can be get sealed from moisture, it will last longer.

100 LL (low lead) for small engines, is well worth the drive to your local airport.

 

[not2old]

I have to assume that Husky was stored with the carburetor empty. If I leave gas in the carbs of any of my two stroke bikes for more than a week or so, they give me grief. I have to drain the float bowls and let fresh fuel refill them. I put petcocks on all my four-stroke engines, too, and let the fuel run out when I'm done for the day. I dump all the fuel from my chainsaws and run the carbs dry, too. I've cleaned a lot of carbs that sat with fuel in them. I once bought a Kawi KZ1300 six-cylinder bike for half what it was worth because it wouldn't start. I pulled the carbs and cleaned them and rode that bike for years.

Yes the carb was empty. I took it apart to check and found it to be clean. I have a Honda CBX that hasn't been started in over thirty years that I'm trying to get to. I expect to have to clean all six carbs before even trying to get it running.