Yes, I am aware of the ethanol causing problems. I know it caused a lot in personal watercraft. This ATV is a 2006, so you would think that the lines would be ethanol safe. That said, I only use 93 octane in hopes to alleviate this problem. Also, there is no fuel shutoff on this ATV as it has a mechanical fuel pump. Thanks for the suggestions. I put some Seafoam in the tank so we'll see how that goes. It does sit most of the time so you are probably right.
Couldn't you install an inline shutoff valve before the carb? Then turn the valve to shut and run the gas out of the bowl until the motor shuts off? Sounds like a cheap and easy fix.