Small engines do not like ethanol laced gasoline. Cars and trucks tend to burn through gasoline fast enough that it's not as big a problem. Ethanol has a high affinity for water and will take it out of the humid air (most of eastern NA) above half filled gas tanks and jerry cans. John Deere recommends filling the gas tank immediately after each mowing and keeping fresh, full, tightly sealed containers. I counted 7 small engines in my garage from a 2-cycle chainsaw and string trimmer to a 22hp JD lawn tractor. Some years the snow blower might only run once or twice. The only engine I run regularly is the generator because when I want it to start, I really want it to start.
Since spending big $ on the JD 18 mon. ago, I've been known to prowl a tractor forum--yes, people like their tractors just as much as their RVs. The prevailing school of thought among people who collect and occasionally operate almost 50 year old JD lawn and garden tractors is that
StarTron is "the" additive to use for stabilizing fuel as well as eliminating ethanol problems. Not to leave
Stabil out of it, there are two Stabil products including Marine Stabil that also neutralize the ethanol. You do have to look for these products and they may only be in boat stores or boating departments--ethanol is a really big problem in boats. My local Canadian Tire store has StarTron in the boat and small engine departments and the last time I bought it, it was right beside the regular Stabil in the auto department as well. StarTron is a bit more expensive, but I only use one or two bottles a year so the cost difference is irrelevant.
I also don't drive my truck in winter so make sure the last tank is a full tank of ethanol free gasoline and still give it the recommended dose of StarTron. Locations of
ethanol free gas stations can be found on the Internet and I am fortunate to have my closest one be ethanol free. I've been using their gas for years and didn't even know it was ethanol free--now I've noticed they brag about it right on the LCD of the pump.
Henry