Re: 2 stroke storage and shelf life
Although there is degradation of the fuel's octane rating starting the minute it leaves the refinery, I have never experienced enough degradation in winter/summer storage for any of my engines (Snow blowers, lawn mowers, snowmobiles, tractors, weedeaters....). On most of them I do use an additive, but sometimes I forget and even the times I haven't I have never had a problem with storage up to a year. As a matter of fact I just recently got a generator that had gas sitting in it for at least 3 years without running and the darn thing started right up on about 5 pulls. On my boat engines I always add an additive to the last tank of the season. Haven't ever forgotten that one.
As for the oil premix separating, it won't. What you may get is phase separation if the gas has ethanol in it. The ethanol combines with water (condensation or right from the air), and gets to a point where it will no longer stay in solution in the gas. This can cause problems and additives and keeping the tank full can help prevent water from being absorbed.
If you are at all worried about it though, add some sta-bil or another additive. It's only a few bucks and if it gives you peace of mind isn't that worth it?
