2 Cycle Mixing Oil and the EPA

Discussion in 'Lawn Mowing' started by Partsangel, Apr 13, 2006.

  1. Partsangel

    Partsangel LawnSite Member
    Messages: 80

    Your 2 cycle equipment probably came with the instructions to use a mix of 40:1 or 50:1 oil to gas ratio. Bless there Hearts! they need to do this bacause the equipment is required to meet EPA emmissions requirements. There's a whole nother thread could be started on our industry having to comply so heavily with the EPA OK OK this not about them..this about your equipment! I would recomend that you use a 32:1 thats 4 oz to a Gal. this well help protect your equipment from premature wear.

    Have A Great Lawnmowing Season Everyone

    Mike AKA Partsangel
  2. Richard Martin

    Richard Martin LawnSite Fanatic
    Messages: 14,699

    So you would have us lean out the air/fuel mixture to save our engines? How does that work? When you lean the air/fuel mixture it makes the engines run hotter. That is a very bad thing when you're using aluminum pistons.

    When you add more oil to a gallon of gas you are making that gallon of gas bigger than a gallon. Your original gallon of gas is still there, it's just occupying more space. The optimum stoichiometric fuel/air ratio is 14.7 to 1. When you displace fuel in your original gallon of gas with oil you are raising that ratio. Add in winter blended fuels with 15% oxygenates and you are running mixtures that are way too lean. These engines are factory prejetted to run lean to begin with.

    If anything you would want to run less oil so you can fatten up the fuel/oil mixture.

    I use Amsoil at 80:1 and have never had a oil related failure. In fact, I usually run my equipment hard for about 3 or 4 years and then sell it to neighbors. My oldest piece of equipment is a 1997 Shindaiwa T-230 that I used for 4 years and then sold to a neighbor for $100 and he is still using it to this day.
  3. steve45

    steve45 LawnSite Bronze Member
    Messages: 1,325

    I think you mean gas to oil ratio or you'd have a real hard time starting it.

    I've got an old trimmer that requires 25:1. I accidentally filled it from my 50:1 can and it would not run. Fortunately, it didn't do any damage, it just ran so poorly for a few minutes that I realized my mistake.

    I think if you run too much oil you'll probably end up fouling the plug.
  4. saw man

    saw man LawnSite Bronze Member
    from utah
    Messages: 1,037

    The engine doesnt require 25:1 to run. I run a 50:1 mix in a old Chrysler westbend gokart engine that the manufacture wanted you to run straight 30w oil with the fuel.

    I would not run anything with more oil than 40:1! If you have a good oil you can go less oil, like the Amsoil, which I would probably run at 75:1.

    Do some research on oil before you start to nock on the EPA. I'll help www.bobistheoiguy.com Check out the forum and lawn & garden section for more help.
  5. Partsangel

    Partsangel LawnSite Member
    Messages: 80

    I'm not sure everyone here is getting the math right?
    50:1 means that there is fifty parts total and one of them is oil
    (very litlle oil)
    40:1 means there is 40 parts total and one of them is oil
    (some oil)
    32:1 means there is 32 parts total and one of them is oil
    (enough oil to protect your engine)
    To make it simple....
    2:1 means that there is two parts total 1 is oil the other is gas. aka half/half

    Running 32:1 oil mix will help protect your engine better, yes there is a chance of a fouled $4.00 spark plug but thats cheaper than a scored cylinder..

    "I'm Just Saying"

  6. XterraJohn

    XterraJohn LawnSite Member
    Messages: 178

    I don't think your math is right. 2:1 should be two parts gas with 1 part oil, equaling 3 parts. A 50/50 mix should be 1:1. For instance, 1 quart oil to 1 quart gas.

    To the poster above saying that adding more oil to the gas leans the engine out, I don't see how that would be possible. Wouldn't the oil burn in place of the gas?
  7. tb8100

    tb8100 LawnSite Bronze Member
    from TX
    Messages: 1,625

    Why? I'll knock on them anyway. Bunch of liberal hippies. :hammerhead:

    (I know what point you were trying to make, just looking for an excuse to bash liberals :waving:)
  8. jaredslawnserv

    jaredslawnserv LawnSite Member
    Messages: 45

    huh thats news to me.
  9. laxative

    laxative LawnSite Member
    from Ohio
    Messages: 147

    I don't like all the smoke.
  10. Mr. Vern

    Mr. Vern LawnSite Senior Member
    Messages: 632

    Actually, the oil will not atomize like the gas, so the fuel/air ratio will in fact change as stated. Yes, the oil will burn but as a secondary combustion resulting for the heat of the initial combustion of the air/fuel mixture. However, going from 50:1 to 32:1 is roughly about a 1% point change in amount of fuel. If the carb is truly tuned to 14.7:1(ideal ratio), then with the added oil it would be at roughly 14.553:1. Now, I don't have the data to support this, and I may be wrong but I would bet that very few engines are tuned to within 1% of optimal fuel mixture. If we assume that 50% are richer and the other half are leaner than ideal, it would seem safe to say that half of all users would actually end up with a better tuned engine by adding the additional oil.
    Having said that, I agree that 50:1 is plenty of oil for most stock engines - assuming a good quality oil is used.

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