10% ethanol fuel vs ethanol free fuel for boat/outboard motor use?

In previous years i always ran what we in europe call E0 fuel which is octane 98 gasoline with 0% ethanol, this because i know that this is easier on the fuel lines/gaskets and does not attract moist or leave behind residue as much as E10 which is the regular octane 95 with the legal requirement of 10% ethanol for emissions(scam).

However with the recent rise in fuel prices and even normal E10 fuel rising above 2 euros a litre i decided to now switch to the cheaper E10, this because it was more like peace of mind to run the simple carburated 2008 Honda hp 20 4 stroke outboard 380cc 2 cylinder on the fuel more or less designed for modern turbo cars with the higher octane rating, in theory this motor as a normaly aspirated motor should benefit from a lower octane fuel.

My only concerns are:
- Because ethanol is hydroscopic the fuel absorbs moisture from the air, all modern cars have vacuum sealed fuel system/tank so that is not a problem. However my boat just has a oem plastic 25l tank with a vent screw on the cap. The tank is in outside air/rain etc.. and is not covered. i can not close the valve because i tried this before but if the sun kicks in it almost explodes because of the pressure build up:ROFLMAO:

- My honda owners manual says that the system is designed to run max 10% ethanol fuel, i use the boat a lot and eventhough it doesnt consume a lot its more or less empty every month so i dont see the deteriorating of the ethanol as hazard like it is with a lot of classic vehicles.

-Outboard motors run at lower water/oil temps and eventhough my engine sees a lot of hours at full throttle 25 knts the nr1 problem with (carburated) outboards is fuel diluition at (cold)trawling speeds which is invitable. Last year my oil also came out pitch black like it came out of a 15k oci diesel engine oil change and smelt like gasoline.
Will the ethanol/fuel in the oil be a reason for problems because the motor spends its life in such a humid enviroment? I mean problems that can be created by the ethanol.

Let me know if you have any experience on this topic and if theres something i am missing out on.

-Powerwise do you think there will be any (marginal) difference? This is not a 2.5 bar boost world rally car but a carburated 380cc 2 cyl 4 stroke with 20hp. Generaly speaking the lower the octane the more power it would have. It has no knock sensors so everything is fixed.
Don't dare leave E10 in there over the winter.
 
I always run E0 in my toys and boats in the last tank of gas or in anticipation of the last tank along with marine stabilizers.
Zero issues in my OPE using stabilized E0 exclusively in them and my fuel cans also.
I have no love for fuel system cleaning anymore, so a little more fuel cost outweighs and prevents aggravation.
 
I always run E0 in my toys and boats in the last tank of gas or in anticipation of the last tank along with marine stabilizers.
Zero issues in my OPE using stabilized E0 exclusively in them and my fuel cans also.
I have no love for fuel system cleaning anymore, so a little more fuel cost outweighs and prevents aggravation.
E 10 Chevron with Techron, stabil,and a dash of Ring Free runs great in my 2 stroke. Very hard to find E0 down here.
 
All I can tell you is 90% of my business is cleaning and repairing boat injectors for marinas, E10 is responsible for a lot of injector and composite fuel tank damage, I see it every day.
Unlike car engines boats live on water, the fuel gets saturated with absorbed moisture and at some point it will drop out. The moisture gets into the injectors and corrodes them. I am doing a set today that have rust inside the injector from a metal fuel rail
Would that depend on the boats usage? It seems most recreational boats sit more than they are used.
 
From my other thread on ethanol fuel damage to a low usage car that sits for extended periods;
f carb deposit 17.jpg


Avoid alcohol blend fuels if possible. That said, and I'm just learning ocean boating and the marina environment, our marina's fuel is supposedly 'treated' by the supplier to moderate ethanol issues and I don't hear of as many issues there as with the lake boat (fueled from a can) crowd. Do your homework on your fuel supplies and use a reputable additive if necessary.

Here is our marina's fuel provider for reference; Valvtect Marine Fuel
 
If there is one near you, QuikTrip has E0. They have been building new ones in Texas like crazy in the last few years.
Thanks. I think the E0 is a county by county thing in North Texas. Motor runs fine for 20 years on E10.
 
I did not know about this and ran cheap ethanol gas in our boat the last two years. Now it's sitting with some type of fuel problem. And I used Marine Stabil as well.

Don't know if it was the fuel but it will be E0 from here on out.
Hopefully just some dirty carb jets.

Always E0 91 octane in marine use or anything with a carburetor.

I have a 90 hp 1985 Johnson 2 stroke. The manual doesn't even say anything about ethanol because it wasn't around then (requires 86 octane minimum). It has seen 91 octane E0 its whole life. Had to rebuild the carbs a couple years ago due to trouble with warm starting. After 35 years the carbs were clean as could be, the needles were just worn. I put Seafoam marine, Startron, and Techron marine in the gas tank (and oil, the VRO system broke a decade ago and not worth fixing) and never have fuel or storage problems. My other small engines get Seafoam and Startron and never a fuel problem.
 
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So boating season is comming to an end. I have used e10 fuel the whole season and did not have any problems. I do have to say that i use the boat a lot so fuel never really gets older then a month.

If i would have stored the engine i would drain the tank and put a liter of e0 in it, however i decided to pull the carbs anyway because this Honda BF50 is new to me so i have checked them all and readjusted so faults that are probably the cause of the bog when suddenly giving full throttle. (2 out of 3 jets where dirty and the the play on the accelarator pump should be 4 mm and it was 8 so it kicked in too late)

I have cleaned every thing with brake cleaner so will store the engine like this for now.

There is still 20 liters in the tank but i will probably throw that in the car and let the tank dry out for the winter. Then the water will dry aswell and the dust/dirt will settle and can be vacuum cleaned out if there is any present.
 
Just a followup, ive been using the e10 ethanol fuel now for over a year and also during the winter storage (its only like a month so dont know if you can really call it a winter storage) and ive had zero problems.

The engine is used at least once every 4 weeks and in the summer times much more offcourse.

I know a lot of boat owners who fill up the tank after every use because they are afraid of running low eventhouh they sometimes only used up a couple of liters, however i am pretty good at estimating on how much i need for a trip and usally run the 55l tank down to about 5/10 liters before i fill it up again, this so i know that after refuelling its almost all "new" fuel again.

The fuel ventilation screw is always open so the ethanol fuel can always reach "humid" air.
Ive seen examples where fuel stored in an open bucket looked completelt emulsified with moisture after 2 3 days and would have expected this would be the main problem being close to the water in an open boat.

Regarding the fuel system/hoses i had zero problems aswell, honda also prescribes that its allowed to use up to 10% of ehtanol so its designed for this.

Just a followup on this topic to show that you can run ethanol fuel without problems as long if you use it regulary.

Offcourse do what you prefer/feel comfortable with.
 
I would use E0 if I could get it. But since I can't then E10 is what I will end up using. I agree recent engines driven on a regular basis should not have an issue with E10 gas.

But that does not help the old Carver boat owners whose gas tanks melted when then switched to E0 gas.

Having said that except for the corn lobby in Congress I am not sure there is a need for E10 gas anymore.

Let the oil company refine gas and add the proper additives to meet EPA standards. They can obviously do that as premium (high test for us old guys) at Stewarts in NY was E0.
 
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I would use E0 if I could get it. But since I can't then E10 is what I will end up using. I agree recent engines driven on a regular basis should not have an issue with E10 gas.

But that does not help the old Carver boat ownership whose gas tanks melted when then switched to E0 gas.

Having said that except for the corn lobby in Congress I am not sure there is a need for E10 gas anymore.

Let the oil company refine gas and add the proper additives to meet EPA standards. They can obviously do that as premium (high test for us old guys) at Stewarts in NY was E0.
Yes thats true, however here in europe e0 is useally only sold as premium sports car fuels and then it will useally be 98 or 102 octane fuels.

This honda is designed so it doesnt require race fuels and can run on ****ty fuels (useally not even available in western europe) so in theory it should perform better on the lower octane then the higher octane fuels. In reality the difference will probably not be noticeable, only in your wallet.

I've built a high performance high compression honda k24 car engine with a mate of mine and that absolutely required 98 or it would knock all over the place.
 
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