Thread: 2 stroke shelf life

It's been in the ground only a few million years before today

AFAIK as oil it is probably fine, as a lube for an outboard it is probably fine, as a lube in an air cooled engine (chainsaw, mower etc) it is probably not so fine.

But if it is just to save a few buck$ ......



Hopefully we will read the knowledgeable comments of one of our oil gurus in due course.

If in doubt, throw it out and buy some new oil. Its not that expensive.

If in sealed containers, it should be OK. If it has been in contact with air, it would be suspect, but in my view still likely to be satisfactory.

As far as the base oil is concerned, the only issue is loss of light ends by evaporation. Two stroke oil is a lot less complex than modern engine oils, which are required to keep water and combustion products in suspension for long periods, as well as having modified molecules to increase viscosity at high temperatures. The only special requirement for two stroke oils is the ability to stay mixed with petrol, and I doubt the additives to do this age readily provided the container is sealed to prevent moisture ingress.

Thanks fellas, well there you go...there was I thinking that it would be more of a complex oil than engine oil. Learn something every day. Yes, I think I may use it if I end up with an old engine...but may not bother if it is a newer engine.

2 stroke oil only spends a fraction of a second inside the engine But it does need to be up to spec to be able to do it's job efficiently So if in doubt throw it out, There is nothing worse than a gummed up or seized outboard to completely stuff up a fishing trip.
However if the oil has been stored in a sealed container and kept in a cool dark spot there shouldn't be anything wrong with it, I usually buy a 5ltr bottle and decant it into 1ltr containers that usually last me a few years as I now only have a small 15hp outboard that uses bugger all fuel and even after a few years there is nothing wrong with the 2 stroke oil I put away in the 1ltr containers.
It's up to you, If you know for certain that the oil hasn't been contaminated and has been stored correctly then it is most likely that there is nothing wrong with it.
However if you are unsure about the oil dump it and buy some new oil, It is a lot cheaper than replacing whatever you want to use it in.