Ethanol gas in a 2-stroke?
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Posted on Thursday Jun 17, 2010 at 10:16 PM  
I was wanting to know if it is harmful to run ethanol gas (mixed of course) through a two stroke. I've had some say its fine, and some say its not good. i got in a pinch and filled up my tank w/ premium gas 10% ethanol. Can this cause any trouble? Its a '73 20hp merc.
Posted on Thursday Jun 17, 2010 at 11:44 PM  
only way it'll cause too much of a problem is if you let it sit in the tank too long because the water in it will seperate ... you might get some of that stabil that's made for ethanol type gas and that might make it work better. you also might run som "Heet" in the tank if you've let is sit a while with that ethanol ... heet will remove the water but I'd recommend you stay away from the ethanol completely or get rid of it if you're out of the pinch you were in. but, that's the only problem I've seen with it ... my sponsor had a guy what kept bringing his boat to them and he was getting his gas at one of those ethanol places there in stillwater ... oncue or something like that and the motor would run fine for a while after ya got it going but if you trimmed it up it'd start cutting out and what it was doing was burning the water off but then it would allow the water to poolup in the carb and when ya tilt it up then a straight shot of water would go through the jet and it'd start cutting out and die ... they finally got this guy to quit buying gas from oncue and it's not gave him any trouble at all since then.
Posted on Friday Jun 18, 2010 at 8:28 AM  
I've been buying my gas at a little convenience store in Claremore that advertises Ethanol free gas for over a year now. Last Sunday, I happened to look at the pump and noticed a sign that said, "Contains up to 10% Ethanol" I looked at that kind of funny as I was putting gas in the boat and then I noticed the sign over the premium "91" button that said, "100% Ethanol".

Boy, did I feel stupid... Unless they just changed it, I've been paying an extra 20 cents a gallon more for ethanol gas in my boat for over a year now...

That brings up another question. I've always heard that its best to run 87 octane in an outboard. Would it be safe to run that 91 octane in my '85 Mercury 175?
Posted on Friday Jun 18, 2010 at 8:59 AM  
Ok thats helpful Tiny. I didnt have the trim up (actually had it down all the way) but it would go good there for several hundred yards (at about 15mph) and then it would bog down. I figured it was cavitating, which i still believe it was. I'm a boat and motor novice still, so i dont know all the tricks yet. Keep 'em coming guys, thanks
Posted on Friday Jun 18, 2010 at 9:10 AM  
DO NOT PUT ETHANOL IN OUTBOARD MOTORS OLDER THAN 1998 -- the gaskets in the internal engine are NOT COMPATIBLE with the alcohols in Ethanol -- continued use of Ethanol gas in such engines will soon cause you carb trouble, it will break down fuel lines, and it will SCRUB premixed oil out of the cylinders resulting in premature engine failure -

Don't know how I can say it any clearer -- in a bad spot and you have to use it be sure you run it all out -- and the NEXT time you get gas add a lead stabilizer to the next tank

Older outboard engines ARE NOT compatible with E10 or E15 blends

There are service bulletins all over stating this -------

Reasons Boat Engines Have More Problems with Ethanol Gas:

Boaters, often store gas in tanks longer than recommended for E10 (90 days).
Cars, unlike boats, usually replace fuel every week or two, which will successfully prevent the possibility of water-contamination/phase separation.

Boat engines live in a water environment - Alcohol gas loves to absorb water.
Ethanol E10 gas can absorb large amounts of water into the fuel tank, MTBE in conventional gasoline did not.

Plus, boat engines usually last longer than cars. Still owning and using a marine engine from the 1970's or 1980's is not uncommon. * These older engine parts and tanks were not usually designed or tested to withstand the damaging effects of alcohol gas.
* Several older marine engines (made prior to 1992) have plastic and rubber parts, and fiberglass tanks that are NOT compatible with E10 alcohol fuel.

EPA, 1995 Bulletin lists several measures "you should do" to protect your marine engine from ethanol, read:

Fuel-Testers, a division of Earthly Solutions.

EPA - Environmental Protection Agency.
RFA - Renewable Fuels Association.
NMMA - National Marine Manufacturers Association.
ACE - American Coalition for Ethanol.
EAA - The Leader in Recreational Aircraft Aviation; FAA Federal Aviation Administration.

"Ethanol as Fuel for Recreational Boats", Dartmouth College, March 2004.
"New Regulations for Gasoline Marine Engines", California Environmental Protection Agency, Air Resources Board, (800) END-SMOG.
November 2006, FAA - EAA Warning against using fuels containing ethanol.
NREL - National Renewable Energy Laboratory; Golden, Colorado; "Issues Associated with the use of higher ethanol blends".
EPA - U.S. Environmental Protection Agency; National Vehicle and Fuel Emissions Laboratory, Ann Arbor, Michigan.
Evinrude Outboard Manufacturer Service, Owner, Repair and Shop Manuals.

The Outboard Wizard - October 2006, Update January 7th, 2007

Stricter monitoring and compliance of Gas Stations and Gas Companies needs to occur, to ensure the fuel at the pumps never contains more than 10% alcohol.
Labeling of Gas Pumps, when ethanol is added, should be mandatory in ALL STATES.
Older marine engines should be exempt from using alcohol fuels...

The Outboard Wizard for more ethanol information and engine troubleshooting advice.
(631) 991-4491 or 631-514-1525

Ethanol's adverse effects to boat motors involves all types of performance issues and disintegration and deterioration, drying and clogging of engine parts.

Signs and symptoms of ethanol problems and damage include:

Stalling, prematurely worn engine parts, rusting, clogging of fuel filters and carburetor jets, release of gunk and sludge throughout the engine, frequent water-contamination/phase separation of fuel, and eventually engine breakdowns and death.

Ethanol can cause a motor to run lean on fuel, due to water will not burn, which will take the place of fuel.
Vapor lock (fuel starvation) is common when using ethanol fuels.

Alcohol fuels are very prone to phase separation, when the weight of the ethanol and water will sink to the bottom of the fuel tank and get picked up by the motors fuel system. (Even small amounts of water can harm the fuel system).

The initial symptoms, (of using a higher than acceptable concentration of alcohol in fuel, is usually engine stalling when you demand acceleration (WOT).

You'll notice other performance issues, such as increased stalling, misfire, hesitation and difficulty maintaining boat speed during trolling.

The long term dangers of ethanol (and other alcohol-blended fuels) are many, including deterioration of parts (rubber, aluminum, fiberglass etc.), rusting, fuel system clogging, and other varied damage to engine parts and components. Older engines are more prone to ethanol alcohol damage.

The most reported and troublesome issue with marine engines and ethanol fuel has been regarding the decomposition of certain fiberglass gas tanks. There really is no solution to this issue, other than to replace the tank (very costly, time-consuming project); Lining or sealing the tank, for added protection, is sometimes possible.

1. It is dangerous to use greater than 10 % ethanol in marine engines.

Some gas supplies are illegally much higher. Check gas with an alcohol fuel test kit to make sure ethanol present is less than 10%.

A recent post on a Long Island, NY message board states,
"Believe it or not, some of the fuel samples tested 48 % ethanol and most were above the 10 % 'maximum allowable by law'.".

All marine engines sold in the United States are designed to operate on fuel containing no more than 10 percent ethanol. Engines built before ethanol became popular for environmental reasons, (past 10 years) have minimal safeguards from the damage alcohol fuels will cause.

2. Ethanol absorbs water - Water molecules combine with petroleum (gas) in your gas fuel tank and lines...
Ethanol has an increased risk of fuel water-contamination due to ability to absorb H20.
(Ethanol attracts and absorbs moisture from the air). Vapor lock and fuel starvation can occur.

The gasoline you pump in your tank may be dry, but due to condensation (from humidity, temperature, etc.) water does exist in your tank. Since water is insoluble in gasoline, it sinks to the bottom of your tank -
As long as it remains below the level of your fuel pickup tube it will not affect your engine. The problem is water is soluble in ethanol and will travel thru your engine fuel system.

A water/ethanol mixture, being heavier than gas, will sink to the bottom of the gas tank, leaving a lower octane gas on top. This low octane gas (lean fuel) can cause performance issues with 4-stroke engines, and can cause damage to 2-stroke engines.

Excess water in engines will also cause premature rusting.

3. Ethanol is an amazing solvent and cleansing agent.

High levels of ethanol can dissolve, deteriorate and breakdown solid material, including rubber, plastic, fiberglass and even aluminum and steel.

Ethanol will also cleanse and release corrosive matter (gunk), varnish and rust, which will travel through the engine and clog fuel filters, carburetor jets and injectors. In many outboard engines it will also contaminate the fuel present in your fuel tank.

Ethanol tends to dissolve certain resins, which can travel through the engine intake and coat intake valves, causing sticking and bent pushrods or worse. This has been well documented for boats equipped with certain fiberglass gas tanks, made before the early 1990's.

The more gunk (rust, sediment, dirt, etc.) collected in your outboard engine over the years, the more noticeable the cleansing effects of alcohol will be noticed.

Ethanol's solvent and cleansing abilities can lead to engine failure and expensive (avoidable) repairs.

4. Ethanol can wear-down and dry-out the plastic and rubber parts in your engine.

Rubber seals and plastic material used in older boats are often not compatible with alcohol. Ethanol will make engine parts dry and brittle. Since ethanol is a cleansing and drying solution, it will clean the oil right off the internal components of a 2 stroke, Extra lubrication is necessary.

5. Ethanol blends can cause additional contamination by reacting chemically with MTBE fuel blends.

Do not mix gas that contains MTBE with ethanol E10.

Mixing MTBE fuel with ethanol blend fuel can create a gel-like substance that clogs passages in carburetors.
Stalled engines and engine damage are the result. Fuel injected engines have shown less damage, than carbureted engines, from this gel-like substance.

6. Engines with older fiberglass gas tanks have the greatest risks when using fuel with ethanol.

Fiberglass gas tanks can "deteriorate" from ethanol, causing this degraded resin stuff, (you'll see "black sludge") to circulate through your engine, coating intake manifolds and building up on intake valves - which basically destroys your engine.

1. If possible, try to avoid using ethanol fuel blends in your outboard and marine engines.

If you are unable to obtain alcohol-free fuel in your area, you SHOULD TEST THE FUEL YOU BUY to assure the ethanol content is at or below 10 %.

2. Follow engine manufacturer gas recommendations. Check with your marine motor manufacturer and/or check your owners manual.
3. Always use fresh, high-quality gasoline and replace it every 2-4 weeks.
Always avoid storing gas in tank for greater than 90 days. Remember that gas with ethanol has a shorter shelf life - use it up and replace it quickly.

Buy gas from busy gas stations - Fuel turnover is faster, gas will be fresher.

4. Check your gas tank for the presence of water and remove all water before adding an ethanol blend.

5. Avoid running on bottom of gas tank (where most water will sink).

6. Do not mix MTBE and ethanol-blended fuels.
Run out or remove your old (MTBE) fuel before putting the new ethanol fuel in your tank.

7. Make sure your motor is equipped with a water separating fuel filter.
Evinrude E-Tec's, and other newer engine models have them, other engines may or may not. The installation of a water separator in the fuel line will help with small amounts of water. Some marine engines are also equipped with water sensors.

8. Check fuel system for contaminants and clogging and replace your fuel filter often.
Fuel filters should be replaced at least every 50 -100 hours.

9. Evinrude - Johnson 2 + 4 fuel conditioner will stabilize fuel, inhibit corrosion and absorb moisture (water) without adding alcohol to the fuel. Add fuel conditioner at every gas fill-up.

10 . Evinrude (OMC BRP) also recommends carbon guard be added to the fuel tank each time you add gasoline, (Reduces possibility of rusting, piston ring sticking and carbon build-up, better overall engine performance, increases engine life), but it will not remove water.

11. Keep your engine well-tuned and lubricated.

12. If your engine has an older fiberglass gas tank, replace it. (Check with manufacturer if your tank was designed to tolerate alcohol fuels). Newer fiberglass tanks are double-lined and made of special material that holds up to ethanol.

Posted on Friday Jun 18, 2010 at 9:39 AM  
Got a neighbor in the lawnmower business, he told me a couple years ago not to run ethanol in any small engine. I'll run some through my 150 now and then, just maybe six gallons in a tank that's already half to 3/4 full of straight gasoline, but I try to use gasoline as much as possible. I run gasoline in the little four stroke, and gasoline in the mower, chainsaw, trimmer, all that stuff.

BassSER, the 66 on the north end of town switched to ethanol a week or so ago...Smitties and a couple of others still sell the good stuff.
Posted on Friday Jun 18, 2010 at 9:50 AM  
Well thanks Obee. I put about 5 gallons of ethanol gas in my tank on tuesday and ran it about 20 minutes. It ran worse after 15 minutes. Could this be my problem. I'll go get rid of that gas and put the good stuff in. and do you think i did any damage?
Posted on Friday Jun 18, 2010 at 10:10 AM  
It just depends -- if the ethanol loosened up crud from your gas tank OR from your- carb bowl as it "cleaned" the internal engine - you could already be in trouble -- however its doubtful it caused any immediate problems -- One of these days I wanna test the E-10 at the Conoco's around here -- I put some in my van the other day and went from 23MPG to 18MPG over the same course -- tells me there is more than an E10 blend at some stations -- The only OnCue where you can get Gas without Ethanol is now the one on the corner of Main and Lakeview.
Posted on Friday Jun 18, 2010 at 10:18 AM  
I put ethanol in my trucks but it never touches my boat, there is 2 stations within 1 mile of my new house that sell 100% gas and have decent lots for getting an expedition with a 22' boat on the back in and out of
Resident forum pirate... YARRR
Posted on Friday Jun 18, 2010 at 12:33 PM  
Dont use it at all! My 1978 model 85 horse Johnson has suddenly come up with a dead cylinder(55lbspsi compared to 125 on the other three). I have run whatever gas I could find conveniently through it for 6 years now and just added stabil ethanol treatment if need be. Obviously I am not certain that this is the downfall of my motor but I can tell you its not worth the chance to me any longer. Gonna end up costing me a bore out and rebuild or either a new/used motor this winter
Posted on Friday Jun 18, 2010 at 12:43 PM  
Originally posted by Ol Slick

BassSER, the 66 on the north end of town switched to ethanol a week or so ago...Smitties and a couple of others still sell the good stuff.

Yep, I saw that in the paper that a few gas stations switched a couple weeks ago!
Posted on Friday Jun 18, 2010 at 1:03 PM  
Did you say it said 100% ethanol on the gas pump. I thought 85% (E-85) was as high as they went. If it says 100%, make shure it doesn't say alcohol free. I thought they only designed engines to run up to 85% alcohol.
Posted on Friday Jun 18, 2010 at 2:30 PM  
I'm pretty sure he meant 100% gasoline. I find myself accidentally saying that every now and then too. Well thanks for the info guys, i'll get rid of that gas as soon as i get home. Also, should i put any kind of lead additive or any other treatment through it? Again its a '73 20hp merc 2-stroke
Posted on Friday Jun 18, 2010 at 2:34 PM  
What ethanol does is SCRUB two stroke premix oil from the combustion cycle -- so it doesn't hurt on your next tankful in addition to normal oil premix to put in a lead additive to restore some lubrication to the ring area of the piston, or run a slightly richer oil mix -- it will only cause a little more engine smoke --

Our Goobermint didn't take into account the millions of two stroke engines still in use --
Posted on Friday Jun 18, 2010 at 3:08 PM  
Okie21, cavitation is what happens when your prop gets too close to the surface and starts to collect air from the surface making your engine rev a lot higher because there's less resistance on the prop ... if your motor is bogging down then the ethanol is most likely breaking down some and you're getting water in your carbs ... it'll most likely die if you were to trim the motor up because the water is down in the bottom of the bowl right now and when you tilt the motor a little it starts putting pure water into the jet and will most likely foul the plugs and it won't run at all. get rid of the ethanol as soon as you can and you can run a little heet in your tank to get the water out of your carbs
Posted on Friday Jun 18, 2010 at 3:41 PM  
Ya Tiny that was my understanding of cavitation, so i wasnt sure why it was bogging down when i had the trim all the way down. I just thought "oh damn, its cavitating like i've heard about". Anyhow, i'll do all this stuff and see how it does this weekend. Thanks for all the help, and where can i get "heet"?
Posted on Friday Jun 18, 2010 at 4:35 PM  
Walmart and most auto parts stores.
Posted on Friday Jun 18, 2010 at 7:51 PM  
ok thanks upDUHcreek. i'll have to go make a run
Posted on Saturday Jun 19, 2010 at 2:36 PM  
Originally posted by upDUHcreek

Did you say it said 100% ethanol on the gas pump.

Okie21 is right. I meant ethanol free. I knew what I meant...
Posted on Saturday Jun 19, 2010 at 4:15 PM  
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