I use Sta-Bil in the fuel for all my small motors. Really helps with preventing water from the ethanol evaporation doing nasty things. Also, if you have an engine that is not running right due to the ethanol issues, add some Marvel Mystery Oil to the fuel. Maybe a half cup to a gallon. MMO is mostly a solvent and will really clean the fuel system.
I use Sta-Bil now and had them add a fuel shutoff. Will try the Marvel Mystery Oil. Used to use that when I was a teen in my car.
The thing that aggravated me the most was I run the gas out at the end of the season and empty the tank, but the repair guy said it got me during the long down times between uses during the winter. Here in Central NY it's snow for a week and dry cold for two. That's why I had the shutoff added.