Old 2-stroke fuel

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mick

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Will it do any harm to use a can of last season's 2-stroke mix in my outboard? I drained every last drop from tank/carb/pipes to prevent gumming. I'm not bothered about the cost of new fuel but it's just such a pain to get rid of the old stuff.
 
I always keep it from one year to the next BUT I always transfer it to metal cans, I only keep cans that are full with minimal air space, I always filter it though a fine filter before reuse and I usually mix it 50:50 with fresh fuel.

The only time i had any trouble was when I did not filter it but i think that was an unfortunate coincidence of not bothering on the one occasion it needed it.

Any doubts then use it for the lawnmower, give it to the neighbour for his lawnmower or stick it in a car that does not have "a cat".
 
Nigel (ex-forumite, self-confessed fuel analyst) used to say that it was light that caused the additives in fuel to go off. I just started my mower the other day. I just dribbled some (old) fuel into the carb, put the air filter back on and it fired up straight away.
I'll be starting a Seagull and a small Tohatsu in the next few days (if it warms up a bit) the same way.
 
Some people may be lucky, but my plugs fouled up something rotten a couple of years ago, and I only solved it by using fresh fuel.
 
I have found that adding a bit of fresh petrol freshens it up a treat. I reckon it's because it's the volatile petrol that mostly evaporates. You may be running with a slightly weaker oil/fuel ratio, but so what?

If it still doesn't work, use it in non-cat vehicles, or add, a bit at a time to fresh mix.
 
My strimmer stood for seven years with a tank full of fuel while we were ex-pats. It was used maybe once per year, although there were years when we did not return home at all. When we returned permanently the strimmer ran perfectly on the same tank of fuel. The fuel can that contained the same batch of made-up two stroke continued to run it well, and has since been used to run a generator and a chainsaw. It has very recently been exhausted, more than ten years old.
 
[ QUOTE ]
Nigel (ex-forumite, self-confessed fuel analyst) used to say that it was light that caused the additives in fuel to go off

[/ QUOTE ] Well he owned a fuel testing laboratory. He employed qualified scientists to do the fuel testing.
Anyway exclude light and air I think you will find. That's really why i transfer mine to metal cans from the plastic fuel tank and only keep full cans. Polyethylene is permeable to oxygen, although I don't know if it is sufficiently so to affect the fuel stored in plastic. It might be.

Funnily enough I have found the Seagull sensitive to stale fuel when i have used poorly stored stuff in it. So is the Flymow! I don't know about the Evinrude as I am more careful about that.
 
Depends a bit on the engine. An old style points and coil type ignition on (say) a Seagull might well struggle unless there is a goodly proportion of new fuel. My previous Mariner with Jap electronic ignition seemed able to run on anything that wasnt diesel - and it probably would have on that if I had tried it. Sadly the Mariner corroded and I'm left with the Seagull /forums/images/graemlins/frown.gif
 
I cut my lawn on Friday for the first time this year. My (4 stroke) mower would not start/run using last year's petrol that had been stored in a 1/4 full plastic can over winter. Adding an equal quantity of new petrol and it went fine.

I have also had the same problem with my outboard (2 stroke) on one occasion.
 
[ QUOTE ]
Anyone know why 2T shouldn't be used in a car with a cat?

[/ QUOTE ] No but its not worth the risk. Neither of my cars has a cat but one's diesel. Suspect petrol goes in the other.
 
Using a new-in-September-2007 Tohatsu 3.5 , it just seems to need to spend longer with the choke closed and ticking over before engaging gear the longer I keep the fuel. I last filled the airtight plastic can last September and have used the engine at least once a month since for runs out to Forethought.
 
[ QUOTE ]
Anyone know why 2T shouldn't be used in a car with a cat?

[/ QUOTE ]

Nope! Just passing on someone else's fears really. But they are d*mn expensive to replace, so why take the risk?

In fact, my '96 mondeo has a cat & I wouldn't worry about putting 2T in it as the car is a grotty workhorse, already past it's sell by date & owes me nowt.

Any one want a black, & rust mondeo with several dings & a VERY short MoT? /forums/images/graemlins/laugh.gif /forums/images/graemlins/laugh.gif /forums/images/graemlins/laugh.gif
 
Diesels (probably not the more modern common-rail type) will run with a bit of petrol in the tank. If you ever make the mistake of starting to fill a diesel with petrol STOP, move to the diesel pump and carry on. They reckon half a gallon of petrol in a tank of diesel isn't a problem.

(I've done it with an old Rover 218D)
 
Dead right. I managed to half fill my 200tdi Landy with petrol. Stopped and filled up the remaining space with diesel. Ran, but smoked a bit and was desperately underpowered.

Topped up with diesel at every opportunity. after about 40 liters or so she was getting better, changed the fuel filter and a another 75% fill of diesel and she was back to normal.

What an idiot. I've owned the car for 10 years.
 
You might get away with it on older diesels, but if there's a lot of petrol in the tank of a new one, IMHO, it's time for the RAC.

The London Ambulance Sservice has a mix older petrol Leyland DAFs and new diesel Mercedes, with the inevitable result. A spate of injection pump failures coincided in nearly every case with someone filling up with petrol and driving til it sounded funny...

Funny lot the blokes (and blokesses) in green: I'd trust most of them with my life, but not with my car!

Back to the thread. My Tohatsu 3.5 has sat since October, but started today - in the snow - on the tenth pull. It would have gone sooner, but I owe it a new plug and it was too cold to go and get the tools
 
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