At the risk of sounding like a broken record, I have to say this: Any gas you store/keep in cans for use in those small motors, such as trimmers, mowers, (and yeah, mini bikes,) should be high octane gas. Additionally, it should be kept "treated" with StarTron (the stuff in the blue bottle). Using higher octane gasoline and keeping it treated has made my life a helluvalot easier over the years. I'm sure many of you have read stories of people who had to rebuild carburetors, replace fuel tanks, lines, etc. Never have I ever had to do any of this to any of the many small powered products I own. I'm sure most would agree that many of these problems we read about could obviously be the result of ethanol. That said, I don't really believe the degradation of an already low octane gas serves to help in any way.
I credit having been a New England boat owner for most of life to coming to know how to effectively deal with both low octane gas, and (especially) ethanol enhanced gas. Leaving gas in your boat for 8 months over the winter has a way of teaching you a lesson you might never forget. And once again, using a relatively low octane fuel in your vehicles will generally never pose a problem as it has the ability to electronically compensate for its combustion. Besides, it's cheaper, and it works, right? Unfortunately, most small single cylinder motor applications just aren't that sophisticated.