petrol addative

[ariadne]

Will a petrol addative help 1 year old fuel used in a 4 stoke outboard

[ranger58sb]

Is it straight gas (petrol)? Or does it have ethanol mixed in?

In the former case, maybe. Might not even need an additive. In the latter case, I'd be skeptical; none of the additives available here that I tried were worth more than about 1 month.

OTOH, that was in a 1-cylinder, 2-stroke, low horsepower carbureted outboard. Perhaps a two- (or more-) cylinder higher-displacement motor, and/or perhaps with fuel injection, the outcome could have been better.

How many gallons or liters, depending on where you are? Most old gas (petrol) will run through cars relatively easily...

-Chris

[a64pilot]

I have used Sta-bil for lawn motors, weed eaters, blowers, chainsaws etc for years and never had a carb problem.
Maybe I’m just lucky, suppose?
However I do not treat old gas, it’s too late then

[rbk]

If unknown, how much are we taking about? 2 gallons, 20 or 200? If is for a dingy OB and <5g is that much fuel worth pulling and cleaning the carb, drain fuel lines, replace fouled spark plugs, filters etc etc or just go and buy another $15 worth of fresh fuel?

[denverd0n]

Originally Posted by a64pilot

However I do not treat old gas, it’s too late then

This ^^^^^


All of the treatments out there are meant to be put in the gas while it is still fresh. Do this and they can keep it fresh for a very long time. I have never heard of any treatment that will "revive" old gas. Though, as mentioned, if it has no ethanol in it, it might work okay as is.


Personally, I would find a proper place to dispose of it, and get new gas. Even if you're talking about a couple of hundred gallons, that's still a small price to pay compared to ruining your engine.