Hi octane gas does contain ethenol. Where I live (MN) only a few stations carry gas that is ethenol free. Octane has nothing to do with it.
I have had dozens of small engines over the years. I have never had a problem with ethenol destroying carbs or fuel pumps. People have to blame something I guess.

Quite a bit of new OPE engines are sporting a sticker on the gas tank (or near it) to NOT use e85 gasoline. I've never seen such a choice at MY pumps...lowest octane has always been 87. Other Octane choices range from 89, to 91 to 93. I had always assumed ALL gas contained about 10% ethanol the past few years (decade??) as those labels had been prominent on pumps for a while. My ASSUMPTION (dangerous, I know) was that the e85 had a >10% alcohol content...but this from Wikipedia:

"E85 is an alcohol fuel mixture that typically contains a mixture of up to 85% denatured fuel ethanol and gasoline or other hydrocarbon (HC) by volume. On an undenatured basis, the ethanol component ranges from 70% to 83%. E85 as a fuel is widely used in Sweden and is becoming increasingly common in the United States, mainly in the Midwest where corn is a major crop and is the primary source material for ethanol fuel production; however as yet, there are about 1900 filling stations selling E85 to the public in the US,[1] and, until recently, only three in Canada.[2][3] It is also available across most of the Maxol chain in Ireland.

There are questions about the use of biofuels like E85, ostensibly to reduce carbon emissions, when they may have a large carbon footprint according to one study.[4] This topic is currently under debate."

I suspect that the e85 furor, the engine stickers I've noticed, the pump stickers claiming "10%" and opinionated mechanics are 'manufacturing' a myth that extrapolates damage from 10% alcohol fuels sold in most of the US.

I've not seen it. Last 20 years I've been seeing the same old problems: dirt, water and 'aged' fuel. It does not improve with age... Perhaps the alcohol even helps dissipate some of the water that works its way into our small engines...

IMO it's the dissolving of the seals. It will actually eat fuel line hose in weedeater, chainsaws, and blowers fuel tanks if left setting long enough. the water may play havoc on the carb. but, water don't dissolve the rubber parts. So you get double Wammy! if not stored properly or left unattended for months. Rust in the carb. and dissolving of the rubber and plastic parts left sumerged.

Ethanol is all that has been available in our area for 10 years or more. I use it without reservation or problem in everything including a 50+ year old Wisconsin engine. I do not use any additive and leave the gas in thru the winter.

E85 is quite another thing and relatively few engines, including automotive engines, are equipped to use it.

Walt Conner

Well, there is some very different opinions, for sure, about whether ethanol is bad for small engines.
IMHO it is as bad for the rubber and some of the plastic gasket material as if it's an acid. The mere fact that gas in a storage container, whether that is the gas tank for your small engined equipment, or the 2 or 5 gal can that you hold your gas in, it will separate, and become "bad" after about 90 days. It cannot be "sloshed" in the container to remix. When it separates, its like oil&vinegar salad dressing. It is emulsified, but never really mixed. It will just re-separate. And it produces some sort of change in the actual gasoline molecule to become something different. I know after my 150 hp boat motor blew a hole in a piston, and it is believed by the boat mechanic to be because I had left it setting since last summer and had not added any additive to guard against that happening. So result was, water in the fuel and bad gas, both for a 2 cycle motor is bad news! I now use the new Stabil (dark blue color) in all my small engines and give free advice to all my customers, to use an ethanol treatment, no matter what.

I am always puzzled by reports such as above. We have a van which has averaged 3,000 miles or less a year for the last 4 years. It has a 25 gallon gas tank which is generally kept at least half full and sits for a month sometimes without being started. The above mentioned 50+ year old Wisconsin sits thru the winter with whatever is left in the tank when I finish as does our 15 year old Kohler on the ridding mower, string trimmer, leaf blower, garden tiller, lawn edger, etc. All are old. No gasket or gasline problems. The darned Wisconsin started unexpectedly on first pull 2 years ago after sitting all winter, ran over my foot and nearly broke my foot and ankle. Old rope pull start tractor.

Maybe a change in brand of gasoline is called for in some cases.

Walt Conner

I guess this is one the same tune as climate warming, some of us believe it and some of us don't? I witnessed it when the guy next door brought over his weed trimmer. The fuel line was dissolved inside the tank and the filter was rolling around like a marble. I disassembled the carb and it was plugged and rusted up. When I cleaned the tank out there was some black looking goo in the bottom I actually had to scrap to get it loosen up. I wish I would have taken pictures? wouldn't believe the color and thickness of the crap that came out of that tank.

I will admit he knows nothing about pre-ventive maintenance and his storage technique is throw it down where I'm done and no he knows it all and won't take hints. I even seen him leave his weed trimmer, blower, and chain saw in his wheel barrow for a month or more and we had several inches of rain. No it was not inside. So I figured that played a big part with the rusty carb. but I can't explain the fuel line rotted off a tool that was less than 4 years old??? Took me 4 hours and my own parts stock to get it going. won't get suckered into that again.

In 1983 I bought a new Plymouth car, front wheel drive, with a 4 cylinder Mitsubishi engine. It had an "electronic carburetor." There was an oxygen sensor on the exhaust manifold, with an electric connection to the carb. The carb had a solenoid operated needle valve, that apparently had polymer seals, but I'm not sure what type of rubber. The car ran fine for maybe 30 thousand miles, and then it started having problems. It would start and idle, but no mid-range power. When I took it in to the dealer, they drilled out a passage in the carburetor, and ran the engine on propane, to calibrate the carb. They claimed that it was fixed, but the problem returned. I remembered that the problem seemed to come & go, depending on where I bought my gas. I started using Union 76, which was alcohol-free at that time, and the problem went away. Another source of alcohol-free gasoline was Shell. I'm not sure if this is true today. I ran the car 200 thousand miles, after I figured out what kind of gas it required. Clearly, there are some types of polymer seals that are not compatible with alcohol, and other types that will work OK with alcohol fuel.

The problem is going to get worse see
http://www.reuters.com/article/CARMFG/idUSN0149521120091201

I always found this interested. I have found that I get about 10% less miles per gallon with 10% alcohol blends. ( I keeps records of everything that goes into both my vehicles.) Chemically you are replacing a molecule that can be complete oxydized gasoline, CH4(CH3)6CH4, with one that is partially oxidized CH3OH.

This does not consider the water problem as a mixture of Gasoline and alcohol will dissolve more water that a neat mixture of gasoline. As more water is dissolved less energy per gallon.

Finally if they are trying to cut the Carbon Dioxide emission. The use of alcohol produces more carbon dioxide than gasoline as, unlike gasoline, Carbon Dioxide is created during the fermentation process (production process)use to create the alcohol. Results alcohol produces higher Carbon dioxide levels than gasoline.

I agree that fuel mileage is going to suffer with Ethanol. I also do not think Ethanol is a practical alternative with present technology, best claim is a 1 to 1.3 energy used to energy produced. (I doubt that even) Crude oil is about 1 to 4.0 energy used to energy produced.

Another aspect of this whole ethanol thing is about octane rating. Because the affinity ethanol has for water results in some water finding its way into the mix from absorption of water vapor in the atmosphere, the actual "Octane rating" of the fuel that finally gets into the combustion chamber may be a couple of numbers HIGHER than what is posted at the pump. A higher octane rating means the fuel is LESS combustible than a lower octane rated fuel when burned in a "low compression ration" engine. People get the wrong idea about octane rating and think that if you put "high octane gas" into any engine, you will get more power out of it. What actually happens is just the opposite. If you burn high octane gas in an engine that has a low CR, more of the fuel will exhaust from the engine unburned than if you use gas with a lower octane rating. The high octane gasolines are for use in engines that have higher compression ratios (and subsequently higher compression pressures and temperatures prior to the spark) to prevent pre-ignition of the fuel before the spark plug fires, which causes all sorts of problems of power loss as well as potential damage to the engine.
Any additional water in the fuel mix will serve to increase the effective octane rating, whether the water is there accidently or or not. Also, the space being occupied by water molecules in the combustion chamber.......is space that could have been filled by fuel molecules, if the water was not present, so another this is another thing that slightly reduces total power output. Somewhere "down the road", the technology might be perfected that will permit production of reliable engines featuring "variable valve timing" (prototypes are already running in tests) which will allow the ECU to adjust "compression pressures" in conjunction with feedback from super sensitive "knock sensors". This will provide an actual real time measurement of the octane rating of the fuel being fed to the engine and will make engines able to use a much wider range of octane rated fuels while tailoring the compression to match the present tank of fuel.

I have to agree with you that higher than required octane ratings do not increase power.However I disagree that water raises octane numbers,I think some of the confusion comes from the "water injection" myths in automotive culture.To increase power in WWII aircraft engines,it was found that the fuel/air mixtures for "best power" were too lean to run for any long period due to overheating of the upper cylinder leading to detonation and other damage.To allow for leaner mixtures at take-off and "war emergency power" water was injected into the supercharger inlet,Methanol was added as anti-freeze and did not increase power.There was a valve in the system to lean out the mixture when water was being used and rich up when water stopped flowing.

water injection is no myth. it increases the densty of the air. A cooler dense charge increases the air mass there for increases HP, but not that much in piston driven engines due to the inability to correct fuel flow and timing, not fesible in todays engines.

back in the day it paid off big in older aircraft engine designs in B52D's and Kc135A's J57 engines on takeoff for 90 seconds, there turbojet engines can increase thrust up to 50% is some models FYI. Anybody around a SAC 60's heard these screaming down the runway during.

***"I disagree that water raises octane numbers"***
Here is a single excerpt from a lengthy article about fuels and applications.
"Water injection, as a separate liquid or emulsion with gasoline, or as a vapour, has been thoroughly researched. If engines can calibrated to operate with small amounts of water, knock can be suppressed, hydrocarbon emissions will slightly increase, NOx emissions will decrease, CO does not change significantly, and fuel and energy consumption are increased"
You can interpret "knock can be suppressed" any way you like, but I infer that to be equivalent to an effective increase in "Octane number rating" of the fuel. For the full article, click link below.

Here is a link that might be useful: Octane anyone?

You can look in any older "Hot Rod" type magazine and see ads for "water injection systems" to increase power and gas mileage.If you ,examine the "system" you will find it uses manifold vacuum which is lowest at max power,just the opposite of what real "water injection"needs,this is the "myth" I mentioned. I know a little about ADI (anti-detonation Injection) systems, as they are called on older piston aircraft.I'm an FAA licensed A&P Mechanic and actually worked on aircraft using these systems. I also attended Flight Engineer school on the same aircraft (DC-6B)I've also worked some on Reno Unlimited air racers,that make much use of water,in fact most of the racers have one wing full of gasoline and one wing full of water,it's sprayed on oil coolers and radiators as well as into the intake system.I noticed the author of the referenced article mentioned the loss of 80/87 and 100/130 avgas and the problems caused by the use of 100LL.At that time many light aircraft were converted to auto gas. As an Authorized Inspector I approved some of these conversions, the same warning was on every STC (supplemental Type certificate)"Never use fuel containing Alcohol in this Aircraft!)Ethanol raises octane rating if you can keep it mixed.

RC: as I said Automotive,not turbine. You didn't have to have been in SAC to enjoy the noise of a"water wagon" The early 707's had a version of the J-57,and one took off from Love Field 5 days a week at 6AM,right over my house when winds were right.The 707s were retro-fitted with turbo fan engines and the space and weight were used for fuel. The 135 soldiers on, but most have been re-engined with turbo-fans.The modern computer controlled engines could easily be used to control a water system if that were useful.In the early 60"s Olds had a car called the"jet fire" it was a Cutlass with the 215CI all-aluminum v-8 equipped with a turbosupercharger,also had a fluid injection system for high power,the fluid had an exotic name and was expensive,there was a warning to never use water in the system The water system on turbines had a drawback too, A BAC111 had the water tanks filled with jet fuel and melted the hot sections on take off resulting in a crash

Pretty cool stuff. My hats off to you folks with all the airplane knowledge. Might I suggest a collaborative effort on a plane engine powered drag mower? Now THAT would be cool. . .

Aircraft mechanics mow their yards too.If I ran a mower shop I would love for all you owners to leave your carbs and gas tanks full of that wonderful E-10 and come see me in the spring.

I'll tell you dc3, fuel quality issues are what really keeps the shop doors open. I'm sure that is no secret. The nice side effects are folks then have to pay closer attention to maintenance to do it correctly. I rarely touch a walk behind w/o doing regular maintenance as well because of the amount of runability issues. A good service or sales person still tries to educate folks on fuel care. The ones that listen are likely the ones who are going to have to do the PM anyways. Win win.

E10 certainly has been around for many years in the Midwest, and has been approved for use in everything for 25 years or more. Small engines included (check your manual). The recent problem is the rollout nationwide had caused some blending issues. E10 is safe, but it's common for stations to have fuel with far more ethanol in them than they are supposed to. I've personally seen fuel with 14% ethanol come out of an E10 pump. That caused the mower to surge and vapor lock. The customer had to start going to another station where they did a better job of the blending. Due to this, machines that have run great for years are stating to have all kinds of problems.

In some instances a few years ago the high octane offering (91-93) did not have ethanol in it. Thus the recommendation. But finding that is pretty much impossible now.

Be VERY afraid of the talk of raising the nationwide ethanol blend to E15. A hell will break loose with your mowers and vehicles.

Original poster of this thread here. After the replacemnt of fuel pump and carb on my Regent ($360), the mechanic at the Simplicity dealership said to use BLUE Stabil to help protect the engine against ethanol damage. I called Stabil customer service and was told their was no advantage to using blue over red. Now I heard that equpment rental companies are recommending blue Stabil. Anyone have any thoughts or experience with blue?

Blue for ethanol blend gas. Sale gimmic or not? who knowS? IMO if I lived in north where equipment sets all winter in the cold for me it would be cheap insurance or feeling that I may avoid fuel related problems come spring?

But, I would still drain any gas that was left in the gas tank and put fresh gas in when spring rolls around when I want to bring the equipment out of storage. IMO alot of fuel related problems are induced with old gas. I sure some will say I never had any problems!!! YET!

I belong to a certain antique motorcycle club and we have been through this same discussion. )One of the members works at a large refinery on the gulf coast. he was able to find the customer service dept. of Exxon-Mobil,and ask about the shelf life of E-10 unleaded. The answer was "we reccommend that you use our gasoline within 1 month of purchase or 90 days if kept in a sealed container.Some of the members usa 100LL aviation gas,which will keep for 1 year or more