Is Stihl Ultra oil GOOD

Discussion in 'Lawn Mowing' started by 1998tahoe, Aug 1, 2008.

  1. TuffTurfLawnCare

    TuffTurfLawnCare LawnSite Senior Member
    Posts: 668

    If by "lean" you are referring to the air/fuel mixture, then 100:1 is richer than 80:1 as the 100:1 will have more fuel in a single charge on the compression stroke. Since a single intake charge will be the same amount of fuel/oil mix, the 100:1 will have more fuel in the charge than the 80:1 as a larger portion of the 80:1 charge will have more oil, thus less fuel.

    If you were referring "lean" to mean less oil than fuel, then yes you would be correct, however "lean" and "rich" are typically used to describe the air/fuel mixture, not the fuel/oil ratio. ;-)
     
  2. Ridin' Green

    Ridin' Green LawnSite Fanatic
    Male, from Michigan
    Posts: 13,344

    Well, technically you are right, but anyone reading my post can see that I am referring to mix ratios.

    As far as your last paragraph goes, you better straighten out Amsoil.;)

    Amsoil uses the term " Designed for pre-mix applications as lean as 100:1 ratios". I do too because most of us here understand that's what we are talking about when discussing fuel/oil mixes and not carbs.:)
     
  3. TuffTurfLawnCare

    TuffTurfLawnCare LawnSite Senior Member
    Posts: 668

    Never looked at their site to notice that. LOL. its one of those things that, as a mechanic, gets me... To me its like calling a gun magazine a clip while there are clear differences. :laugh:
     
  4. Ridin' Green

    Ridin' Green LawnSite Fanatic
    Male, from Michigan
    Posts: 13,344

    I thought they only used clear clips in toy guns. :laugh:

    I know what you mean, believe me.
     
  5. TuffTurfLawnCare

    TuffTurfLawnCare LawnSite Senior Member
    Posts: 668

    Personally, if I was running fuel with ethanol in them, then it would be wise to run them dry and put them up for storage. Even if you run them, you still have ethanol in the fuel that will attack the rubber and aluminum in the carbs. I have very little faith in fuel stabilizers as the fuel still has ethanol in them. Plus the fuel you get at a gas station still has a shelf life of a few weeks without stabilizer additives, and as I said, I don't trust stabilizers.

    That being said, I am an advocate of using avgas in my 2strokes just for this reason. It contains no ethanol and has a shelf life of over two years. I run it exclusively in the 2strokes, and in everything that gets stored for over a month. The generator is filled with it all year until it is needed. if more than a single tank is needed I will fill up with regular fuel, but for storage it gets avgas. Everything gets stored with full tanks of it during the off season from the 91 john deer to the trimmers and chain saws. After two years of no use, my Husky 357xp saw fired right up and ran like it did before being stored.

    The avgas is leaded, so some are afraid of it or dont like it, but for off season storage it is the best option as it wont let gaskets dry up, wont go stale, and doesn't contain and additives that could cause harm to the tiny carbs on these engines. Avgas can be found at nearly all small air fields and municipal airports. Locally it is $5.75/gal.
     
  6. therock

    therock LawnSite Member
    Posts: 72

    Thanks, We have a non-ethanol gas station here @ 90 octane. Guess I'll run that.
     
  7. TuffTurfLawnCare

    TuffTurfLawnCare LawnSite Senior Member
    Posts: 668

    You will still need to do something to preserve it as it will still go stale after a few weeks. Non ethanol fuel only takes care of half the problem. It will still have a short shelf life. Hence the reason I go for Avgas, long shelf life AND ethanol free.
     
  8. Richard Martin

    Richard Martin LawnSite Fanatic
    Posts: 14,700

    Welcome to Lawnsite where we regularly refer to the fuel/oil ratio as lean on a regular basis.

    Someone wanted to know why we tend to use Amsoil mixed at 80:1? Because the 8 oz bottle of Amsoil mixed into 5 gallons of gas yields a 80:1 mix. It's easy and simple. :dancing:
     
  9. Ridin' Green

    Ridin' Green LawnSite Fanatic
    Male, from Michigan
    Posts: 13,344

    True that, and a quart bottle makes a nice even 32 gallons.
     
  10. ZX12R

    ZX12R LawnSite Senior Member
    Posts: 785

    Interesting,I will take that into consideration when I do make the switch.
     

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