Or you have a very bad mechanic that doesn't have a clue what engine diagnostics mean. Probably charged you $80 for a non-diagnosis. It didn't strike you as odd that 99% of all other cars DON'T have a problem with ethanol fuel?
If you grew up on a farm, why didn't you learn anything?
Tune your small engines to run on ethanol or buy different fuel.
It's not brain surgery; it's rocket fuel science.