Zero Turn Mower. I'm stumped.

Yeah, if I'm gonna put it down for the season, I'l run it out and put a tank of non ethanol AND Sta-Bil in it, but I normally run ethanol fuel in it during the season, because I was using it frequently, so it always ran fine, until it didn't.
Rusty several QT stations around me in Atlanta have started selling no ethanol 87 octane. I have been using ethanol free gas in all my small equipment for years and have had very few problems as a result.