After serious thinking The Natural Philosopher wrote :
Alan wrote:
I bough a gallon can of lead-free petrol when there was all that kerfuffle
about fuel prices a few years ago which has sat at the back of the garage
ever since. During a clear out I unearthed it again and now I need to get
rid of it (especially as we've got a diesel these days).
I tried taking it to the council dump but - "we've got no facilities for
handling liquids guv - do you have a lawnmower?" - yes I do but it's
electric :-).

So the question is - will this old petrol be usable in a petrol lawnmower?
If so, I can pas it on to a mate.


Yes, bit not in its pure state. Old petrol loses the volatile fractions
fastser than the less volatile, so it will have distilled itself a bit into a
less explosive mix.

But cut say 2:1 with fresh, it should be fine.

The key is how much of the can is left compared with when you parked it up?
If its say half gone, its OK, but needs more fresh. If its still more or less
all there, it will probably be fine.

I left a ride on for 2 years unstarted..it wouldn't start. A new can of
petrol on its tank leaving the old there, and it was fine.

They do say that carbs can become gummed up with the deposits of petrol
after being stood a long time unused, but as already said, I have never
had any problem.

--
Regards,
Harry (M1BYT) (L)
http://www.ukradioamateur.co.uk