Fuel for older Evinrude/ Johnson

6

68glasspar

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Will older evinrude and johnson outboards handle a 10% alcohol fuel/ oil mix?
By older i mean pre 1980. Trying to find fuel without alcohol in it is getting very difficult.
 
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Crosbyman

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yes run 24/1 twc3 oil fuel mix nothing wrong with 87 octane 10% fuel use fuel saver additive . I always store fully fuelled and carbs full during winter storage. never have problems.. you can run 16/1 in 1950s OBs and older

50/1 was pretty well the norm mid 1960s and up
 
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cyclops222

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Just remember The unbreakable rule about any vehicle switching to... E 10 ..gasoline.
There were horror stories of the Ethanol in the gasoline dissolving all the varnish and other sludges in gas tanks, fuel lines and carburetor parts. Engines slowed down and stopped. I have never run E 10 in my 1986 and 1998 Evinrudes. I fill up at a Marina that only sells NONE E types of gasoline. I use several 6 gallon gas tanks in the boat. Can always find a gas station with regular gas on a trip.
 
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Chris1956

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Your first tank of e10 will tend to loosen some old crap in the fuel tanks. Be prepared to change the fuel filter after the first tank. Watch the rubber fuel lines for failure. Most fuel lines have already been changed to alcohol-resistant by now, but keep an eye on 'em.

J/E motors after 1964 run a 50::1 fuel mix.
 
6

68glasspar

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My oldest boat is a 1968 glaspar with a 69 evinrude 85hp, I had the fuel tank out last year and had a radiator shop clean it out. 2nd boat is a 16ft lund with a 1978 johnson 25hp., that i believe i may have already run some 10% fuel with amsoil 50:1 and some star-tron additive
 
JimS123

JimS123

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My old boats have 1952 and 1964 outboards on them. Our local govmnt gave us E10 before they actually told us. I have never had gas problems, ever.

The only caveat is that all my motors are well maintained and garage kept.
 
Davetowz

Davetowz

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Another vote for ethanol free gas. Sheetz carries it at most stations around me. (Ohio)
 
6

68glasspar

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I know i can get ethanol free fuel at my local airport and a few gas stations 20mins away! But that wasn't my question as to what you prefer! The question was in general, will older outboards handle the 10% ethanol gas
 
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Nordin

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The engine it self will handle 10% Ethanol gas, but all rubber hoses, fuel pump diaphragm etc parts that are made of or has rubber in it will be affected by the ethanol.
All old parts that not are suppose to be in contact ethanol will swell after avail.
Rubber parts that not are made to stand by Ethanol such as hoses has to be change.
In my opinion the fuel today are not as good as it was 30-40 years ago.
Today I would prefer Ethanol free gas and with a little bit higher octan number to older engines.
Not less than 95 octan (I am in Sweden) and we have 95 octan 10% Ethanol and 98 octan.
I use 98 octan fuel in my older engines.
 
Last edited:
matt167

matt167

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If the carb or fuel pump has been rebuilt within the last 25-30 years, it will be fine with ethanol. If not, the ethanol will eventually degrade the rubber bits. Modern kits come with rubber that is impervious to the damage of ethanol.

This is one very important reason not to use NOS carb or fuel pump kits
 
matt167

matt167

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Nordin said:
The engine it self will handle 10% Ethanol gas, but all rubber hoses, fuel pump diaphragm etc parts that are made of or has rubber in it will be affected by the ethanol.
All old parts that not are suppose to be in contact ethanol will swell after avail.
Rubber parts that not are made to stand by Ethanol such as hoses has to be change.
In my opinion the fuel today are not as good as it was 30-40 years ago.
Today I would prefer Ethanol free gas and with a little bit higher octan number to older engines.
Not less than 95 octan (I am in Sweden) and we have 95 octan 10% Ethanol and 98 octan.
I use 98 octan fuel in my older engines.
Click to expand...
Octane has nothing to do with how old an engine is. It is required for resistance to compression ignition. Too high of a resistance to light off and it might cause issues. Outboards generally recommended 87-89 octane or white gas, which didn’t have an octane listed but was an unleaded product before unleaded was common.

Keep in mind the US octane system is slightly different than other countries
 
dingbat

dingbat

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Almost 25 years has passed since the ethanol hysteria began yet myths and misconceptions still abound.

Ethanol resistant fuel lines have been the norm in since 1986. Highly recommend changing 39 years or older fuel lines prior to switching to E10 fuels.
 
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Crosbyman

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my 1966.... 9622a 9.5hp 1970s Merc 4hp and all others since the 60s & later when e10 existed have all worked fine with lead, no lead, ethanol across 50+years of boating...

I think the solution is regular use , store with FULLY fueled or fully "run dry" carbs. My 75hp ETEC with DI has a sealed fuel circuit ..never had problems.
 
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Chris1956

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Gee, I have had no issue with my carbs in the last 20 years. I think it is because the e10 keeps the carbs and fuel system clean. I run a stabilizer in the fall and leave the carbs full over the winter. In the spring, she starts right up and runs perfectly.
 
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Nordin

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matt167 yes I know that the octane value has nothing to do with the age of an engine, but here in Sweden the fuel today is worser than it was in pre 70s, 70s and 80s.
My experience is that you have to retard the spark advance with todays fuel to be sure you do not got detonation due to preignition.
When I adjust the spark advance on a Chrysler/Force 3-4 and 5 cylinder for example I go from factory spec. 32 dg BTDC at WOT to 28-29 dg.
Todays fuel does not last as long as before during storage.
I never used any additives during storage back in the 70s, just my own opinion and experience.
 
jimmbo

jimmbo

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1964 was the Year OMC went to 50:1. TCW Oils hadn't been created yet. They appeared in about 1966
Some of the 1957 - 1963 OMC Engines could run on 50:1 instead of the Speced 24:1. These were the 35hp and the 40hp models, and all the V4s. They were all Anti-Friction Powerheads, with no Friction Bearings(Bushings)

The Ethanol Gas. Ethanol in Gasoine does tend to act like a Sponge for Water, so a Water Separating Filter is a Good Idea if that is the Fuel used.
Personally I hate the Stuff as it reduces Power and Fuel Economy by about 15%, but there was a Lobby(not allowed to say who) really pushing the stuff...
 
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