Zero Turn Mower. I'm stumped.

There are people on the www who insist you can remove alky by adding water, shaking it, let it sit, and then siphon off the "good stuff". And you can SEE it in the bottom of a clear container.
That's precisely how it's done if You're motivated, it's how the alcohol content is checked in the field, specially graduated test tube add water to line then fill with sample & shake. Let sit and the increase in separation level over the water's initial level shows the % of alcohol. It always priority bonds to H2O over gasoline, it will come right out of solution.