I have posted numerous times referencing my experience with fuels.
Non ethanol is not always "non" ethanol. Secondly and probably just as important, non ethanol is "usually" more expensive and most stations that sell it don't sell that much of it because of the price, therefore it sits in their tanks for a while, potentially picking up moisture, getting old, etc.
The cure? Move south...use the boat year round like I do. Thing is though (in my case)-that even though I do use it year round, in the fall/winter/early spring, maybe once a month instead of a few times a week.
...And yes, that is the ONLY cure, use it. Gas is made for cars. Cars don't sit for more than a week or two at a time on average. AND they're mostly fuel injected, which runs at MUCH higher pressure (30 to 3000 psi). Gas isn't made for small engines anymore.
Sta-bil. It prolongs the inevitable. How long? 85% of my work is fuel system related and a majority of that 85% is due to staled fuel. Of that majority, a good portion of them all say that they did use sta-bil when they put the equipment up the last time it was used. I can't for certain say how much truth there is to it but that's what I hear a lot of. Thus, I can't give any certainty of what actually works other than just using it once in a while. My new motor is EFI but the old one was a carb and I never had a single fuel system problem. It did sit for a few months from time to time but when I say "sit", it was started even if just for a few seconds, without dunking it into the lake. Just sitting there on the trailer, fire it up for a second or two, shut it off. Once a week or thereabouts. Leaving the fuel line attached and the 3 gal tank close to full.
There's also the drain technique and that seems to work too. Remove fuel line quick connect. Remove all fuel lines from the motor, blow them out, blow out the filter bowl, then drain the carburetor bowl and while the screw is out, spray some carb cleaner up inside the bowl drain, then reinstall the screw(s) and you're done. I know guys who do that-and it's a pain but so is cleaning carburetors, and those guys can go years without cleaning carbs. Some carbs are worse than others. I CRINGE when someone brings me a 4 cylinder carbureted 40 or 50hp Yamaha 4 stroke that needs carb repair. Even the 3 cylinder 40's were a bear. Early 2000's vintage.