While this is a hugely debated topic, I found some clarification on the truth of the matter that will forever shape what gas I put in my outboard and when, check it out: Ethanol or Ethanol Free

Not sure what debate you're talking about. If you run your boat like you run your car, which is to say, all the time, then you don't need to run ethanol free. If you take your boat out once a month, then you need to be running ethanol free.

I fall into the latter category. I have been running non ethanol fuel in my boat(s) since I learned of the issue. I do not have to rebuild carbs near as often anymore. Matter of fact, I haven't had to have my carbs rebuilt since I stopped using ethanol based fuel. Simple as that.

20 years and 3 different boats running ethanol and never an issue.

If I owned an outboard manufactured before, say 1990 I might seek out ethanol free... But since the 90's all outboard manufactures have engineered their engines with ethanol in mind. I fish on a pretty frequent basis and have never had a problem with E10 fuels. I've never winterized an outboard.... And I can count on one hand how many times I've ever filled the gas tank full... Just do this whenever you add fuel...
Ethanol treatment and injector cleaner whenever you add fuel to the tank... Dan

PS... I follow the same program with the wife's pontoon... But it sits from say November until mid March with whatever fuel is left from the last time out... And the fuel come next March will be just fine... Dan

Actually it started in 1989. I bought a new bass boat with a new 1989 Evinrude that was set up to run ethonal fuel. I kep that boat until 2012 when I finally bought a new one. I don’t run non ethonal fuel and I have never had a ethonal related problem. But with the new people going to run the country E-15 is something they are gong to push along other putting diapers on cows. So that will present a bunch of issues the outboard motor industry could have to address.

Great info Dan and Tom. Thanks for the input here.

Even fishing once a month there is no need to run non ethanol. I fish about once a month and have used e10 since it hit gas stations. Never used an ounce of fuel additive. And not ever a single issue.

I bought a new boat this summer with a Yamaha 4 stroke. I have been paying the big premium and buying non ethanol fuel and not running the additives. We use the boat 3-4 times a month so the premium on the fuel is expensive. My old boat was a 2 stroke Yamaha and I ran E10 but ran the additives. Should I just start using the additives and buy E10 vs paying the premium for non ethanol? The posts on this thread are suggesting that.

You should run e10 and not waste your money on additives. They don't help with anything

I would at least use ring free in my gas

i've run tha mercs since 1968 with 90% of 'em in tha "hot rod" variety.. did try a few additives on occasion but didn't see any advantage or disadvantage either way with tha influx of ethanol.. sometimes goin' for months without as much as a "jus a start on tha hose"..... last motor i ran was a "stem winder 280" that would turn up over 9 grand at any time... would set with "old" (several months) fuel in it and always started with ease.... jmo.

I am in the camp of no issue with ethanol fuel. I have left fuel for months and not had issues. Actually I would be embarrassed to say how long I have left boat gas between uses . I do use big external spin-on filter/water separators and keep them changed maybe that helps. In my opinion after making sure all hoses and other fuel deliver is ethanol proof there are 2 things to consider with E10. The ethanol works like a solvent. If a boat has been on straight gas for a considerable amount of time the switch to E10 may cause deposits to get broken loose in your tank and fuel lines. So keep your filters changed for some time after the changeover. A much bigger potential issue is phase separation. A reasonable amount of water in straight gas may not be an issue, the filters can capture it if it isn't too much. But get much water in the E10 gas and it can separate the ethanol from the gasoline making for a much bigger mess then the water alone. So, in my opinion, move to E10, stay on E10, don't go back and forth, and make certain water is not getting into your tank through vents, fill cap, etc and you might find it is a non-issue.

I own small engine shop, we use to use gas with ethanol and sometimes folks would wait months to pick up their equipment. We go to start it and it would start and die. So back into the carb we go and it was junked. Switch to non ethanol and never had that issue again.

I believe boat fuel systems are better sealed then outdoor equipment. I believe this makes a big difference. Ethanol gas likes moisture, humidity gets in the tank and it pulls the moisture into the gas. Now most engines are EFI and have water separators.

I personally run non ethanol gas, I fill my tank after each use, have a water separator filter and my motor is EFI. I figure what's a few more bucks in gas compared to a breakdown. Same reason I run synthetic oil compare to conventional. better protection.

Here is a fun experiment you can do with ethanol gas. Take a glass, fill half way with gas, let a fan fan blow over it, give it about 5 minutes, you will have cloudy gas....that is moisture.

I run non ethanol in my boats and small engines lawn mowers, chain saws, weed eaters ect. It made a huge difference in issues! Worth every penny! Everything I own is a carb motor. Maybe the newer motors are made for the ethanol.. I would hope so but I’ll use non ethanol as long as I can get it!