ethanol in the gas

They are now putting ten percent ethanol in all of the gas that is sold in New York state where I live. I was wondering what effects this will have on small engines, especially the chainsaws.
Any information you guys have on this subject will be more than I know at this time.

Ethanol is not kind to the diaphrams and other similar materials in carbs. Here in Minnesota, while we have ethanol in some grades of gas (we are, after all, one of the kings of corn and ethanol), we can still buy non-oxygenated fuel (what we used to call premium) that is higher octane and has no ethanol. I've only ever burned premium in all my small engines, both two-strokes and four-strokes. This non-ethanol gas is for off-road vehicles and small engines, and there are warnings on the pumps not to use it in cars/trucks, but I still pump it into my old 85 Chevy Silverado 4x4. I mean, those older 8-cylinders LOVE their high octane.

You should check to make sure that N.Y. won't preserve some level of non-oxygenated (no ethanol) gasolines.

If you live close to the border of a state that still sells premium gas with no ethanol, it'd be worth a trip now and then. Premium will stand unused for three months before it breaks down, while the regular grade starts breaking down after a month or so.

Ethanol and small engines don't seem to mix well. Here In southern Wi we have had ethanol for about 2 years... In the past year I have done more carb kits/fuel lines/fuel filters than in the previos 3 years combined. Ethanol attracts moisture and will cause major issues with the carbs on chainsaws. Premium here has no ethanol so thats all we recomend, Occasionally we get customers asking then why does my car run fine on with ethanol , well your car/truck has multiple cylinders to help carry it past the low points and in many cases the computer advances/retards timing for fuel quality. A single ore even a twin small engine is old technology no EFI.. yet

Look for Kwik Fill gas stations if there are any up your way.
Around here in western NY, most of the Kwick Fills still sell gas without corn mix.

I am getting ready to buy my first higher end chainsaw. Is there anything that can be done to help avoid the issues that the ethanol creates?

jimdad07 said:

I am getting ready to buy my first higher end chainsaw. Is there anything that can be done to help avoid the issues that the ethanol creates?

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Keep your carb properly tuned and only use fresh mix. I run a string trimmer for a living and have not seen any issues from ethanol other than it shrinks grommets and fuel lines on older OPE..

There are many who have had problems with ethanol. However, I have had to use it for many years in Colorado and have had no trouble, yet, with any saws or any other engines. Perhaps the low humidity here helps. I don't know; but I've had no hassles with it. I am at the airport at least once a week with easy access to avgas, but I don't bother. It isn't an issue for me.

If you think it's bad now just wait. I was watching the US Farm Report, on TV, this past weekend and the ethanol producers are pushing for a 15% ethanol minimum. As much as I like farmers, we have a 40 head cattle farm ourselves, I don't like this idea. If I wanted to run ethanol it should be of my own choosing. My vehicles, the 2 gas tractors, 2 garden tractors, and all the small engines we have aren't designed to run with that much ethanol in it them. We have 3 diesel tractors at least it won't effect them.

This may not be a popular opinion on this site, but I can say that after using oxygenated fuels for far more than a decade it has had little or no affect on the life or performance of my various toys.

It includes 47 years of boating with 2 stroke outboards (I was on the water today), 40 years of off road riding, 27 years of that were racing in the pro class (still own three bikes) and assorted chainsaws, both new and old.

I've used high octane leaded pump gas in the sixties in my muscle cars, to unleaded regular 10% blend in my boat today.

The facts tell me that I most likely saw a slight reduction in HP with the new fuel and that if I store the fuel in a poor fashion there is more of a "chance" of phase separation, or other problems.

Some time in the late 80s or early 90s when we first started using ethanol here there were plugged fuel filters and carbs in older cars and little used equipment. Plus there were fuel line or system issues because there were so many engines made years early when there was no thought of 10% ethanol blends and they used non resistant products.

Most everything made since the early 90s was designed for use with ethanol blends, meaning rubber parts were at least more resistant to it. Many boaters still complain that the blends destroyed parts in their carbs, and, well, it does. These carbs hadn't been rebuilt since they were made in the 70s and were long over due for a rebuild (new kits come with resistant parts and have for a very long time).

As the trend towards 10% blends throughout the country marches on, each new area targeted starts screaming that it will destroy every piston powered thing they own. The reality is they may see some problems as the ethanol cleans out the fuel system, or if the fuel system is long overdue for a rebuild it may cause fuel lines and other things deteriorate, but for the most part that’s about it.


Don’t get me wrong I don’t like blends and I’d rather they weren’t used, I also think it’s a feel good scam. But to say my life has changed much because of them would be a lie.

Automobiles are driven regularly and do not experience many ethanol related problems as the fuel is used up every week or so - and the fuel injected cars with oxygen sensors can adjust the fuel mixture to compensate for the change in the fuel/air ratio required by different fuel blends.

The problems caused by ethanol in small engines are either caused by the fuel mixture being set for a pure "gasoline" mix and they are not adjusted for ethanol blends - or they are caused by using fuel that has gone bad. Fuel related problems are not usually experienced by people that use their equipment regularly and have to refuel often - it is most often a problem when the fuel sits in the equipment for a couple of months between uses. The fuel absorbs moisture and/or the gasoline portions evaporate and leave a high concentration of the ethanol behind. Stihl recommends not mixing more fuel than you can use up in two months - and draining out the fuel and starting the saw and letting it idle until the fuel in the lines and carb are used up if you are not going to be using the saw for a few months.

For those of you who think the Premium does not have ethanol.....you should test the fuel to confirm this as adding ethanol is a great way for the fuel companies to increase the octane rating....all grades of fuel in this area have ethanol blended at 10%. To test for ethanol in the fuel just take a clear bottle and pour water about a third of the way up and mark the level of the water with a marker or some tape. Then fill the rest of the bottle with the gasoline to be tested, put on the lid and shake. The water and fuel will temporarily mix like vinegar and water salad dressing - then when you set it down the water will begin to settle out. If the level of the water has risen above the previous mark - the additional height is caused by the water absorbing the ethanol out of the fuel blend. If the water level does not rise then there is little or no ethanol in the fuel.

Here is a 20 oz soda bottle filled with water up to the tape line:



Here is a photo of the same bottle after having added fuel and the bottle was shaken and allowed to settle. The water level has risen above the tape line as a result of the ethanol that was absorbed out of the fuel.



If you now have funky fuel blends in your area.....just keep the fuel fresher than 2 months and don't let your equipment sit around with fuel in the tank. It is easier to add fresh fuel to an empty tank than it is to repair fuel lines, clean out corroded fuel tanks and carbs or replace diaphragms.

oneoldbanjo said:

For those of you who think the Premium does not have ethanol.....you should test the fuel to confirm this as adding ethanol is a great way for the fuel companies to increase the octane rating....all grades of fuel in this area have ethanol blended at 10%. To test for ethanol in the fuel just take a clear bottle and pour water about a third of the way up and mark the level of the water with a marker or some tape. Then fill the rest of the bottle with the gasoline to be tested, put on the lid and shake. The water and fuel will temporarily mix like vinegar and water salad dressing - then when you set it down the water will begin to settle out. If the level of the water has risen above the previous mark - the additional height is caused by the water absorbing the ethanol out of the fuel blend. If the water level does not rise then there is little or no ethanol in the fuel.

If you now have funky fuel blends in your area.....just keep the fuel fresher than 2 months and don't let your equipment sit around with fuel in the tank. It is easier to add fresh fuel to an empty tank than it is to repair fuel lines, clean out corroded fuel tanks and carbs or replace diaphragms.

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Thanks for posting this simple test. Now, just think about what this implies. If the water layer can absorb ethanol from the gas mix, the ethanol in the gas mix can absorb water right from the air. Pure ethanol will absorb moisture from the air, so the "undenatured" ethanol of commerce is 95%.

So now you shoot this gas/ethanol/water mix into your engine, and you end up with your exhaust containing superheated steam, which over time can corrode all the internal parts.

The key thing is to use fresh fuel, and keep the container tightly sealed. If you can keep water out of the fuel, you'll avoid problems.