We run 10% ethanol in everything but snowmobiles, they only get 91 premium.  For some reason I only have carb troubles with the snowmobiles.  Every year.  Even the 4500 watt generator that sat for 4 years with 10% ethanol ran fine after we put in fresh gas.  I believe I was duped into believing 10% ethanol would hurt snowmobiles.  I will find out this winter for sure because I would rather ride than clean carbs.