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Old Gasoline

C

Cmerc

Contributing Member
The gas in my boat is almost 10 months old (250 gallons) no I did not put stabil in the tank as it usually only lasts 6-8 weeks.
Any recommendations as I am sure it has lost some of its potency.
 
Go for a long boat ride, top off with fresh and add Stabil or you can get a pump from AutoZone or similar for free usually as a rental, pump it out and fill all your vehicles up.
 
Sounds good in Theory, but, No Auto Zone in the bush, no way to get it out and stored, or disposed of.

what exactly happens to old gas anyway, looses octaine?
 
If the tank was close to full you have nothing to worry about just go out and have fun. What contaminates the fuel is water intrusion and with a full tank there should little if any water present.
 
Fuel could be siphoned out using a garden hose,but your going to need a lot of gas cans, Place hose into tank to reach the very bottom,siphon off a gallon, Pour some of that gas into a clear container,Let it sit overnight,if there was any water in fuel it will be in the bottom of container,water weighs more than gas
 
I'd be tempted to just go ahead and use it (as long as the engines seen to perform Ok) but swap out the water separator half way through that batch of fuel just in case there is a significant amount of water.
 
Agree with Bob - use a good octane booster that mostly has MMT (Methylcyclopentadienyl manganese tricarbonyl) (Yes, I had to look that up!)
 
Do like Bob and Chawk say. And, in addition, you can take a SMALL sample, say about the size of a shot glass, and pour it on a hard dry surface in a SAFE location.

Put a match to it immediately and see if it flames up or sputters weakly.

That's a poor man's volatility test and will give you an idea if it will burn well in the engine. If the tank was sealed all that time, it's likely it could still be useable.
Good luck.
 
Thanks guys I added a double dose of startron and a double dos of octane booster, gonna add 100 gallons of gas in a few days.
 
You should be just fine with that approach. If you've been strictly ethanol free gas thats best, then you can just monitor your fuel water separators.
 
Although not on the same scale, my boat last had fuel added in August last year and approx 30 gallons stayed in the tank over the winter with no additive. A couple of weeks ago I topped off the tank with a further 70 gallons and she runs absolutely fine.

That said, here in the UK we have a maximum of 5% ethanol which I believe may be lower than in the US and maybe our weather doesn't produce as much condensation either. My external separator contained just a tiny percentage of water when I swapped it out and the on board separator has never contained any water.
 
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Biggest risk with old gas with ethanol is ethanol turns to water a bit with age. It will smell bad if its "off", I'd just use it up as fast as possible. 10 months is getting close to the life of ethanol fuel IMHO, like was said, check your fuel water separator after each trip. Pour into a clear container and see if the water settles out.

If you have any water in your tank from condensation or ethanol, it will be at the bottom of your fuel tank.
 
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