What does ethanol do to small engines?

Discussion in 'Mechanic and Repair' started by exmarkking, Nov 2, 2013.

  1. DA Quality Lawn & YS

    DA Quality Lawn & YS LawnSite Fanatic
    Posts: 8,899

    Ha, this thread.........
    You guys are all seriously paranoid.
    We have had ethanol in our gas here in the Upper Midwest for decades longer than any of you, and I have yet to have any problem with cars, trucks, handhelds, etc.
  2. ZX12R

    ZX12R LawnSite Senior Member
    Posts: 785

    My dealer did not tell me to change it every year,I just figured for $5-7 per filter its cheap insurance as they are easy enough to change out.

    I am going to call them to see what they say and report back here.Thanks for the number.
  3. ZX12R

    ZX12R LawnSite Senior Member
    Posts: 785

    We have had ethanol here for years also. We used to get it only in the winter months and everyone would complain that their fuel mileage went down. No big deal,it was only for 2 or 3 months. Now we get it year round and its effects do not go without problems.Go to any small engine shop in the northeast and its undeniable.
  4. 04cubcadet3235

    04cubcadet3235 LawnSite Member
    Posts: 61

    I agree. We have had it since 1995, engines actually seem to run cleaner with it. For older engines before that, there is ethonal free gas at most stations around here. Its only 91 though.
  5. TuffTurfLawnCare

    TuffTurfLawnCare LawnSite Senior Member
    Posts: 668

    The bold part is wrong. Alcohol is hygroscopic, meaning it attracts and hold on to water molecules. Gasoline is not, and will not mix with water. In pure gasoline, the water will simply fall to the bottom of the tank and lay there. However, ethanol will mix with the fuel. The ethanol will attract and hold onto water keeping it in suspension which allows the water to make it through the fuel system, into the engine, and out the exhaust (This is the simple science behind "tank dry" "fuel water remover", etc that is sold in the auto part store).

    The problem is when too much water is introduced and the alcohol can't hold it in suspension. It begins to go into phase separation where the water/ethanol falls to the bottom of the tank. It is this phase separation that is the simple science behind determining the amount of ethanol in the fuel.

    i.e. Take a known amount of fuel (100ml)
    Add a known amount of water (20ml)
    Mix thoroughly and allow time to seperate, then drain off the top layer (fuel now without the ethanol and water)

    measure the remaining water/ethanol mix and this will tell you what percentage of ethanol the fuel was.

    100ml fuel
    20ml water
    drain off the fuel, and your left with 35ml of water/ethanol, then your fuel was E15. This can be done, because its the ETHANOL that holds water, NOT the fuel.

    This method can be used to remove ethanol from fuel, but it should be noted that the ethanol is an octane booster to the fuel. So if you remove the ethanol, the octane of the fuel could be dangerously low.

    Since I'm not a chemist, just a mechanic of all things that burn fuel, I run 100LL avgas in all my two strokes, and everything gets stored with it during the off season. 2 year shelf life, no ethanol, and very tightly controlled. In the years I have been running it, I have never had a single problem with any of my equipment, even the Husky saw that with a full tank for 2 years, then fired up and ran like it was new.
  6. Patriot Services

    Patriot Services LawnSite Fanatic
    Posts: 12,966

    Back in the old days up north you learned to keep your tank topped off in winter and threw a bottle of "dry" gas in every tank. When they perfect the 100% conversion of plant material method the percentage will get even higher. They will eventually get it right and build highly ethanol tolerant engine parts.
    Posted via Mobile Device
    Last edited: Nov 10, 2013
    ericg likes this.
  7. 04cubcadet3235

    04cubcadet3235 LawnSite Member
    Posts: 61

    That seems to make sense, im no chemist either and i just work on motors also. I was just going by what one of the so called "chemists" was saying and what ive known from the past the fact that water will still get into a fuel bottle. I should have added that, water can get inside a non ethonal fuel tank/bottle but it will not mix with the fuel. With ethonal it will actually mix with the gas. I think ill do a bit of testing of this all for myself in the spring, ill let you guys know the results if i find time to do it.
  8. ZX12R

    ZX12R LawnSite Senior Member
    Posts: 785

    Hey Richard,the original manual that came with my Walker states that the EFI fuel filter be changed at 1500 hours. The latest online manuals dropped the interval by 1300 hours! They say change it at 200 hours and more frequently under dusty conditions. Gotta point the finger at ethanol although Kohler will never admit that.

    See page 5 for the info:

  9. 04cubcadet3235

    04cubcadet3235 LawnSite Member
    Posts: 61

    That is probably actually not the reason, ethanol fuel has been around longer than kohler had the efi engines. It probably has to due with emissions since the government is pushing harder emissions on engines. Look at caterpillar and international, you don't see those engines in trucks anymore, the fact they could not make emissions. You go on internationals website now, your not going to see the DT466E in their trucks anymore, they are using cummins now. Or they could have cheapened the filter and now it is not as good. Ethanol is not as bad as you think... I laugh at all these stores around here with "ethonal treatment" products everywhere and people buying them for their brand new mowers/ tractors, engines etc... People think that ethonal is bad for everything, and it wears the internal parts of engines, and the people at these places will say anything to the customers about how bad ethonal is so they buy the product. Its a great way of making money for fuel treatment companies, that alone has greatly contributed to why everyone thinks ethonal is bad.
    Last edited: Nov 10, 2013
  10. ZX12R

    ZX12R LawnSite Senior Member
    Posts: 785

    I am not so sure we should be comparing truck engines to lawn mower engines in reference to emissions. Either way I find it strange that Kohler lowered the maintenance interval by such a huge margin by 1300 hours.My guess is that the ethanol dries out the media inside the filter much quicker breaking it down with pieces of it potentially entering the fuel system beyond the filter. Guess we will never know unless an independent unbiased test is performed ,but,I would not hold my breadth over it.

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