Thread: Enthanol?

Is it as bad for outboards as I hear?

Below is an excerpt from an article I wrote a few years back. The short answer to your question is = If you burn large quantities of it like you do in your truck, no real issue. If you burn small quantities sporadically, then treat it like milk. Also, the additives on the market come with their own set of problems and are not a cure all.

"This topic seems to come up weekly around my place. It usually starts out something like this. Someone shows up with a motor that won't start or is running very badly. I ask, "How old is your fuel?". The common response is "It's not the fuel, I just filled er up.". To which I say. "Did you dry out the tank or just top it off?" Their response is "I just put 5 gals. in yesterday on the way to the lake. At this point, I'm looking for my glass jar. I pull a fuel sample. Upon seeing a cloudy mixture of what used to be quality fuel, the conversation turns to ethanol.
The whole topic of fuel, how to keep a fresh supply, how to prevent problems and ethanol in general seems to be at the center of much debate with a wide variety of ideas and opinions. Seafoam. Sta-bil. Which one? Both. Double dose. More oil. Octane ??? A quick search of the web will lead to more questions than answers.

Like everyone else, with the introduction of ethanol came a whole new set of problems for me. Not only was I seeing issues with my own outboard, I had folks bringing motors to me for problems I hadn't seen before. All related to ethanol.

After getting ahead of the curve on what was going on, I developed an almost carbon copy routine of how I explained ethanol and how to prevent future problems to folks that showed up with a fuel related issue. I'm not a chemist, although I do know how to make ethanol. I'm not a physicist, although I can make a rock dance on top of water for about as long as you can hold your breath. I know that with the wide variety of info on the web, you can probably find afew articles that will contradict what I'm about to say. And finally, I'm not selling a cure.

I'm just going to share with you some of what I have learned and give reasons why it happens and solutions to prevent it.

ETHANOL=
It has a basic octane rating of about 100. which makes it a favorable diluent for today's gas. In small quantities, is not bad for your motor. It's ability to disperse water and hold it in suspension has long made it a go-to item when water is present in the fuel system. (ex. Heat). The same quality can also be bad. Not only can it hold water in suspension, it is also highly attracted to it. And that is where the trouble begins. An example that I use is this. Ever seen a capped 5gal fuel tank in the early morning? Looks like it is about to implode. Did you see that same tank at 3pm? Looks like it is about to explode! The warming and cooling of the fuel's vapors makes the tank want to inhale and exhale. And in the morning when it's trying to inhale corresponds to the same time as we reach the dew point. Meaning that a vented tank will inhale a breath of air, heavy with water molecules. As the molecules enter the tank and settle on the cool surface of the fuel, the ethanol molecules will be attracted to the h2o and a bond will form. With only one h2o molecule riding along, the ethanol will remain in suspension. Randomly floating around in the mix. But as the ethanol continues to collect h2o, it becomes too heavy to freely float around in suspension. When this happens, the ethanol and all it's water molecules fall to the bottom. The term for this is phase separation and it's a bad thing. If it stayed clear of the fuel pickup tube, the remaining fuel (now void of a portion of ethanol) is left with less of an octane rating. Which means it will be more prone to detonation, pre-ignition, and the other effects it has on things that go boom in the combustion chamber. Well you ask. What about all that h2o in the bottom of that tank? Well, when it's picked up and begins running through the combustion chamber, two things happen. The first is that the mixture affects the flame front and power output. You will probably notice a drop in rpm and think, "hope that clears up". The second thing to happen is that water will be instantly turned to a super heated steam. Steam. As in steam cleaning. As in steam cleaning that 2stroke oil and cylinder walls. A 2stroke that is acting up is telling you the end could be near. Eventually, with enough water entering the engine, combustion will cease to occur and there you will be until the problem is corrected.

Now, on the long term. Ethanol can be broken down to make an acid commonly referred to as vinegar. Yep. Sugar makes ethanol and ethanol makes vinegar. Make it from barley and call it malt vinegar. Grapes and it's wine vinegar. All you need is a little bacteria and about two weeks. So, we have long term exposer and storage of ethanol in our fuel system. Attached to afew water molecules to assist in it's corrosive attack on the metals and rubber components that make up the fuel delivery system. And with afew weeks of storage in our tank or hose or carb or our fuel injection pump, it's not ethanol any more. It's metamorphosed into an acid. Leaving aluminum and brass with a greenish film of corrosion. (Ex. Carb bowls, idle passages and jets). As for the rubber components including the hose, primer bulb, fuel pump diaphram, carb gaskets and needle tip, the older parts swell and fall apart. The newest parts seem to be more resistant to the exposure."