Ethanol IS bad for your engines

[Maine Sail]

I have evidence of rust in the carburator bowl of my Atomic 4. That's a good sign the tank is degraded.

I have had evidence, twice, of rust in my carb bowl on our Honda lawnmower. It was cause by ethanol physically attracting water and physically rusting the bowl. The tank is plastic..

I would be surprised if your fuel tank was steel, O'day used lots of aluminum tanks, course anything is possible.....

 

[25yearslater]

It's definately steel. Magnet sticks. Bowl, get this, is glass. I know what you're saying about the water rusting metal bowls as I've had the same problem with my lawnmowers. Any additives that help keep the water in suspension or would that be dry gas?

 

[Gunni]

Any additives that help keep the water in suspension or would that be dry gas?

Yeah, alcohol. "Dry gas" is the government name for it.

 

[shemandr]

This thread has made a good case that ethanol could be put to better use.

 

[25yearslater]

Thanks for the confirmation Gunni. Ain't that the truth Shemandr. The stuff is creating all sorts of problems for marine fuel/engine systems. Once my aging Atomic 4 gives up the ghost I will be looking at repowering with diesel. At least that way I can burn vegetable oil if some crazy additive comes down the pipeline that raises Caine with those. It's a shame some marine engine maker didn't consider the multifuel engine common in military vehicles back in the 60's and 70's. Hmmm. Perhaps my next career beckons.

 

[vetch]

The military multi fuel engines work but the maintaince requirements go up with non diesel fuels. I think diesel is the way to go in a boat if you can keep the algae out

 

[Indysailor]

Here's a recent experience with ethanol and my 4hp Tohatsu.
Engine has been running well this spring- completely winterized last fall, new plug, drained all the gas, fogged the cylinder.

The place I buy ethanol free gas from was out of it so I had to use E10 the last few weeks. Ran the motor through about 1/2 gallon of the stuff, everything worked fine. My wife commented on how well she thought it was running. Topped off the integral tank before we left after our last sail, closed the tank vent.

Didn't have a chance to sail for a week and a half. Went to the boat yesterday and on the way picked up new gas. Motor would not start. In pulled the tank, drained it, drained the carb, the fuel filter and emptied as much gas as I could out of the lines and refilled with fresh gas. Motor started, ran rough, but once the remnants of the old gas were through the carb, it ran fine. We sailed for three hours, fired up the motor on the first pull and went back the marina.

The gas I put in was ethanol free this time and I'll be interested to see what happens next week when we sail again. I'm beginning to think that stabilizers and trying to run the motor out of gas are probably less important than keeping the gas as fresh as possible. Last year, with ethanol free and no Sta-bil or Seafoam, the motor ran well all season.

 

[Witzend]

I guess I'm lucky. My 6HP Tohatsu sat all winter with E10 fuel left in the carb, really no way to drain it with out major disassemble. Using the same gas I had left over in the external tank, she fired right up no problem. Have run her a number of times since, no problems. I have a 1970 Sears tractor with an old 12hp Briggs on her and she sits all winter every winter for 42 years now, and it fires up in the spring with the same gas in the tank every time. Why am I not having any problems?

 

[Indysailor]

I've heard that emissions standards have had something to do with it, which may explain why the old tractor fires right up. Draining the gas on that 6hp is not too difficult. I just did it yesterday at the slip.

Not sure what the difference is, but obviously once I switched the gas out, the motor ran very well. I'm real interested in seeing what happens next time I'm there.

 

[Dantodd]

I guess I'm lucky. My 6HP Tohatsu sat all winter with E10 fuel left in the carb, really no way to drain it with out major disassemble.

Uh... Take the top off and look at the carb bowl, there is a plug sticking out the side on the bottom of the bowl. One lever plus one screw to drain the bowl. Now spray carb cleaner into the carb (right through the screen) and it will drain out the bottom of the bowl. Finally, shoot a little cleaner into the plug hole and your carb is clean and won't be effected by water/ethanol.

 

[DJN51]

Instead of draining bowl ,Yamaha Mechanic said to disconnect fuel line and put fitting on motor to run fuel out of carb and all lines.Also said to add 1 0z 2 stroke oil to gas helps to lubricate system.My motor is 6hp 4 stroke

 

[jibes138]

I have a 20 HP yamaha and when I fired it up this year with old fuel it started right up then died and wouldn't restart. I emptied the carb and the fuel came out clear. Hard to believe fuel in the bowl would change form over the winter from gas and ethanol to pure water, so my question to the community is whether the ethanol separates from the gasoline when allowed to sit. After completely flushing the fuel system and starting with fresh gas it ran fine again. This is all with e10, I will be looking for E0 from now on and running it dry.

 

[thinwater]

I have had evidence, twice, of rust in my carb bowl on our Honda lawnmower. It was cause by ethanol physically attracting water and physically rusting the bowl. The tank is plastic..

I would be surprised if your fuel tank was steel, O'day used lots of aluminum tanks, course anything is possible.....

PS is running tests on e10 corrosion and the effect of moiture absorption, sea wate rcontamination, and corrosion inhibition by gas additives. It's going to be late summer by the time the testing is finished, but I do know this much; some of the additives really do slow the corrosive effects of e10 (and some make it worse).

Metals are being tested in multiple galvanic pairings, so we will see the effects on steel tanks and the effects on aluminum carb bowls with brass drain plugs.

 

[kenn]

Mercury Marine issued this paper on ethanol myths and facts last year. They claim that E10 is ok for modern engines. This paper may be a push for their own additives, but Mercury have a pretty good reputation for outboard technology.

In particular, they claim that E10 cannot pull enough water out of the air to lead to phase separation. They claim the primary source of water in fuel is condensation - water condensing out onto a cool tank wall. It's almost the same thing though... the water came from the air...

I'm fortunate that we can get ethanol-free gas, and I do not keep gas over the winter, I just dump any boat gas into the truck, and start fresh in the spring. No gas problems.

 

[Indysailor]

Last month I filled with E10 because there was no E0 fuel available close by. Boat ran fine for the few days, then I went to SC for a week and upon return yesterday I couldn't get it to start.
After draining the integral fuel tank (Tohatsu 4st/4hp), the bowl, the fuel filter and getting as much of the fuel out of the lines as possible, the tank was refilled with fresh fuel (E0). The motor started and ran very rough, would only stay running on half choke. Drained the bowl again and started it. It ran progressively better until after about 10 minutes it was running perfectly, presumably because the stale gas had been run through or drained out. This part probably has nothing to do with the ethanol content, but rather just getting the old fuel out (with the accumulated water).

A couple observations: fuel drained from the carb bowl into a small spray can cap showed water droplets very clearly at the bottom of the cap. Also, there is a lady nearby who's boat has a newer Tohatsu 4st/4hp and she mentioned that her manual recommends 89 Octane, with fuel cleansing additives. My manual (2009) simply recommends 87 Octane, but warns against using ethanol. At this point, I'm wondering whether Tohatsu may have made some slight changes to the carb on later models, or if they just felt that higher Octane fuel (ethanol or not) is the best way to guard against problems.

Generally, I'm beginning to believe E10 in these motors is all right as long as the boat is run very regularly- like once or twice a week at least. Otherwise, forget it. With the integrated tank, the fuel is fed to the carb from the bottom of the tank, which means any water that forms from condensation is going directly to the bowl. If I continue to have supply problems with E0, I'll consider switching to higher Octane.

 

[Witzend]

Mercury Marine issued this paper on ethanol myths and facts last year. They claim that E10 is ok for modern engines. This paper may be a push for their own additives, but Mercury have a pretty good reputation for outboard technology.

In particular, they claim that E10 cannot pull enough water out of the air to lead to phase separation. They claim the primary source of water in fuel is condensation - water condensing out onto a cool tank wall. It's almost the same thing though... the water came from the air...

I'm fortunate that we can get ethanol-free gas, and I do not keep gas over the winter, I just dump any boat gas into the truck, and start fresh in the spring. No gas problems.

This is a quote directly out of the Mercury paper:
"Fuel Care Myths"
"E10 Gasoline pulls water directly out of the air:
–There is no active transfer mechanism for ethanol molecules to reach out and
“grab” water molecules out of the air. Under normal storage conditions, even in a
vented fuel tank it just does not happen at a level or rate that is relevant
–The primary cause of water collecting in fuel tanks is condensation from humid
air. This water runs under the fuel and collects in the bottom of the tank. The
volume of air that can move into the tank is reduced when the tank is kept full"

Is the first part of this statement true or false?

 

[thinwater]

In particular, they claim that E10 cannot pull enough water out of the air to lead to phase separation. They claim the primary source of water in fuel is condensation - water condensing out onto a cool tank wall. It's almost the same thing though... the water came from the air...

Their statement is about 50% true. I have done many experiments, some still on-going, looking at additives, corrosion, and vent filters. I have also reviewed the calculations.

Tanks. If you turn the gas 2x per year, the tank cannot absorb enough to separate. But it can absorb enough to slightly increase corrosion potencial.

Can this be reduced? Yes.
http://sail-delmarva.blogspot.com/2012/02/gasoline-filtration-complete-overkill.html
But don't bet on the EPA-carbon filters on the new boats to do the job. Because they were the logical result of agency momentum and expereince with cars rather than real science with boats, they contain carbon, wihch is the wrong material, both in terms of water absorption AND gasoline evaporation.

Carb bowls. Yes, the fuel can separate, nearly 50% of the time in the right conditions. First, there was some water in the gas to start with from tank absorption, then the bowl absorbes more because of it's much higher temperature cycling and higher surface/volume ratio, and then finally the ethanol evaporates and the fuel becomes unstable and separates. Leave a jar out with the lid ajar (not wide open--too fast) in a damp place (every marina is) and you will get separation.

Can this be prevented? Yes.
http://sail-delmarva.blogspot.com/2012/03/carburetor-vent-canister.html

 

[Indysailor]

A little update on experimenting with E10 and E0 this year. After running both I have seen no difference in the amount of water that ends up in my system. Two days ago, we had a storm run through our area, about 3/4" of rain. Prior to the storm, I had sailed and put the motor to bed by running it out of gas- turning off the fuel switch and closing the integrated tank valve.

Yesterday, my son and I went to the boat and started the motor and it stalled after a couple moments (using E0). We pulled the starter chord then drained the carb a few times, gradually pumping the water into the carb bowl and getting it out. Eventually, the motor started and ran strong. We put the drained fuel in a plastic bottle and measured about 1oz. of water at the bottom of the bottle.

The motor has run well during this very dry Summer, but it seems wet weather (especially when it rains) is affecting it, causing condensation in the fuel lines/carb. That's my guess anyhow. It's not a big deal, as draining the carb only takes a few minutes, but perhaps I'm beginning to see the same stuff that is in the report, that it's not necessarily the fuel as much as it is the moisture in the air causing the problems. 1oz. seems like a lot of water, but I'm not sure of a way to prevent it other than installing a water separating filter, which may not fit inside a 4hp with integrated tank.

Earlier in the Summer, when we had a little more rain I had experimented with not running the fuel lines dry, but the result was the same. Honestly, I'm not that sure it makes a difference either way. I have noticed, however, that the motor runs a lot better on E0, but I suspect that gas may also be higher octane. The chuckleheaded kid at the place I buy it had no idea and there was no rating on the pump.

 

[RECESS]

When we had a 9.8 Tohatsu on our ODay 25, I would disconnect the fuel line from the outboard and run it dry after each use. I only used ethanol free fuel in it. I did not want residue from the fuel gumming up the primary jet over a long stretch that we did not sail. I have had bad experiences with E10 and outboards. I have access to ethanol free so that is what I use in my dink outboard, EU2000 generator, and lawnmower.

 

[Don S/V ILLusion]

This seems like another academic exercise with no scientifically or statistically valid testing on which to draw any logical conclusion. For example, how do we know with certainty that the water collected in a tank after a rainstorm was not the result of rain leaking into the tank purely by physical transport? The act of simply tightening a tank cap is meaningless in this context.

There is a wealth of sound information from which you could draw the conclusion that ethanol is hydrophylic. We already know that!

Are there places in the U.S. where people, after doing some due diligence, cannot buy av gas or non-Ethanol gas that this is a problem?