Should I be using Non-Ethanol Fuel and SeaFoam

JohnnyGuy

Petty Officer 2nd Class
Joined
Aug 24, 2017
Messages
176
Hey all,

My brother restores and work on lots of OLD Lawn Boy's from the 50's, 60's, 70's etc...
He has always told me to use non-ethanol premium fuel in my two strokes as the ethanol in the fuel tends to leave a "gummy" residue and has the tendency to build up gunk and clog the carb, etc...

I have a new to me 76 Johnson 15HP which I'm sure likely never used premium fuel. The tank the motor came with was a 3gallon and had approximately 1gallon still in it.
I topped it up today with a non-ethanol based fuel (premium octane) for an upcoming trip.

Should I be worried about any gunk coming loose because of the switch in fuel? I know sometimes the additives/detergents in the premium fuels can loosen old deposits which can lead to blockages, etc...

Moving forward, what do you all recommend for long-term "durability" I feel more comfortable with a non-ethanol based fuel based on my brother's recommendations and his experience with the older smaller carburated motors. Would adding SeaFoam to the tank be a benefit as well, or am I just throwing my money away?

I'm in Ontario Canada and the non-ethanol fuel I typically use is Shell V-Power Nitro+.

Thanks in advance.

Cheers,
JohnnyGuy
 

RCO

Petty Officer 1st Class
Joined
Jun 15, 2016
Messages
350
The problem with ethanol fuel only shows up when it sits. If you use all the fuel in your tank within a month or two, you'll never have a problem. I do prefer to use non-oxy in my small engines, just because they do tend to sit over the winter (or summer), with some Sta-Bil if I know they are going to be unused for any length of time. You won't have any problems, or performance change running a higher octane fuel with or without ethanol. The higher octane fuel additives are to prevent detonation and pinging in higher compression engines, and make no difference in engines that don't need it. Sea-Foam works pretty well to remove carbon deposits as needed, but there isn't any benefit to running it on a regular basis.
 

alldodge

Moderator
Staff member
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Mar 8, 2009
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40,581
My opinion
Seafoam is snake oil but sure wish I bought stock in it years ago
E10 gas will go bad but takes at least a year.
Will use stabil in E10 if gas has a chance of going more then 8 months, otherwise use nothing
 

ondarvr

Supreme Mariner
Joined
Apr 6, 2005
Messages
11,527
Your motor doesn't require premium, it's a waste of money, but some people only believe in E-0, so it may be the only option if you fall into that category.

You don't need to use anything in the fuel unless you plan to store it for a while. And a long time isn't a few weeks.

Your motor is old enough that the original parts aren't very ethanol resistant, but at that age if these parts haven't been replaced they should be just from age, the new components will all be E-10 compatible.
 
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Tony T.

Petty Officer 2nd Class
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Jun 5, 2007
Messages
178
I usually always run the gas out of the carbs on my outboards also the gas line when done using them and depending on the gas how old I'd probably used it as a parts wash if it's pretty old instead of just topping off the tank, but that's just me. I use Seafoam and Star Tron for additives. I was having trouble with the float sticking in the carb on a 2001 Honda fourwheeler after I parked it from riding it, another words park the fourwheeler in the shop and about five minutes later I'd start smelling gas strong and it would be leaking on shop floor. Before I tore into the carburetor a fourwheeler mechanic friend I worked with said get yourself some Seafoam and try that first before you tear that carb down, I did and the Seafoam cured my problem, it never leaked again right up to the day I sold it three years later,so I guess the snake oil Seafoam worked out for me and I've run it ever since in my fuel tanks or the Star Tron. To each his own the way I see it.

Tony
 

444

Senior Chief Petty Officer
Joined
Jul 16, 2010
Messages
704
I have never found sea foam to do anything. I have tried it many times, for me at best it works as a fuel stabilizer.

In general I prefer non-ethanol fuel for my small engines. I find that when ethanol sits it absorbs moisture and leaves a white crusty, chalky looking build up inside the carb. I have worked on several that were so bad that this started to eat away at the aluminum carb bodies leaving them pitted even once cleaned. Fortunately I have still found the carbs to be usable after cleaning but boy is it a pain to clean that crap off. I'm also in Canada and the Shell Premium is what I use in my boat and keep around in a jerry can for all my small engines.
 

Tony T.

Petty Officer 2nd Class
Joined
Jun 5, 2007
Messages
178
I have never found sea foam to do anything. I have tried it many times, for me at best it works as a fuel stabilizer.

In general I prefer non-ethanol fuel for my small engines. I find that when ethanol sits it absorbs moisture and leaves a white crusty, chalky looking build up inside the carb. I have worked on several that were so bad that this started to eat away at the aluminum carb bodies leaving them pitted even once cleaned. Fortunately I have still found the carbs to be usable after cleaning but boy is it a pain to clean that crap off. I'm also in Canada and the Shell Premium is what I use in my boat and keep around in a jerry can for all my small engines.
I agree on the ethanol gas to what you said, I would love to run non-ethanol gas here in my area but it's a 60 mile round trip for me to get non-ethanol gas.

Tony
 

Silvertip

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Sep 22, 2003
Messages
28,758
It was said earlier that "ethanol problems only show up when it sits." That's not true but what is true is that IF your engine was built BEFORE the advent of E10 fuel, it was built with rubber parts and some gaskets that are not ethanol tolerant. Next, if the fuel system for that boat and engine has collected gunk and varnish over the years, ethanol is an excellent fuel system cleaner and it will loosen that crud and clog filters and if it does get past the filter(s) will clog carb passages. So blaming ethanol for cleaning up gunk in your fuel system is like blaming your banker because you overdrew your checking account. Once the system is clean and rubber parts are replaced with "modern" pieces, the engine will not know the difference in the fuel. If there are some really serious water absorption issues in your area you might install a fuel/water separating filter. Then go boating. And yes -- high octane does nothing for your older motor unless it actually "required" high octane. High octane retards detonation which means it is harder to ignite than lower octane fuel. Engines (like car engines today) have knock sensors and ECU's that can advance timing automatically until detonation is detected optimum performance is achieved. Your engine does not have that capability so high octane fuel is a waste of money and gains you nothing.
 

82rude

Rear Admiral
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May 8, 2012
Messages
4,082
My earliy 70,s 6 hp johnson runs happily with e10 as does every small engine i own.My 4 wheeler may sit 10 months and starts and rns great after that time with e10.4 wheeler does get gas stablizer though.
 

Sea Rider

Supreme Mariner
Joined
Sep 20, 2008
Messages
12,345
Being just a 3 gallon container, burn it all in last outing and store a empty tank if sitting for long time periods. For my 2 strokes horse non or E higher octane fuels, no fuel additives whatsoever, just apply an over dose of CRC carbon remover through carb with OB-running each 50 worked hours, will remove most of the carbon deposits around piston and cylinder head along idling much smoother.

The only possible way to check if fuel additives used on a constant basis are doing their work right inside combustion chamber on a new OB from day one will be to remove cylinder head and have a look, other than that, keep using it could result in a complete waste of cash...

Happy Boating
 
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Rstacy

Seaman Apprentice
Joined
Sep 22, 2017
Messages
33
I don't know if I would call Sea Foam snake oil but it isn't far from it.
Sea Foam is not a strong problem solver but it isn't a bad problem preventer and that's important.
Having been in the golf car business for a few years I can assure you that ethanol is not good for your engine. Putting fuel stabilizer in doesn't help. The ethanol is still there.
Ethanol free is the only way to go. Unfortunately around here you can only get that in high octane gas. Yes the high octane is a waste of money but the ethanol free benefit is not.
I read an article a while back claiming that the ethanol free program was going away. It didn't deliver on the benefits and the problems were many. I haven't heard anything since reading that.
 
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