Premium Gas for 2-Stroke Engines?

Discussion in 'Mechanic and Repair' started by BlackVCG, Sep 12, 2004.

  1. BlackVCG

    BlackVCG LawnSite Member
    Messages: 10

    What kind of gas do you guys use for your 2-Stroke equipment? The local Stihl shop says 89 octane is the minimum, but you might as well get premium to ensure that you're going to be safe.

    As far as I'm concerned I've always ran regular 87 octane in all landscaping equipment I own. 2-stroke and 4-stroke. Never had a problem, but I haven't owned a Stihl product until now.

    Thanks for the input.
  2. vipermanz

    vipermanz LawnSite Bronze Member
    Messages: 1,773

    i've never had a problem running 87 octane
  3. grass_cuttin_fool

    grass_cuttin_fool LawnSite Gold Member
    Messages: 3,526

    I have been using 87 octane in stihl for 2 years now and I dont see any problems

    UNISCAPER LawnSite Bronze Member
    Messages: 1,426

    The best gas to run in a two stroke if you can find it is white gas. It is the only gas lawn boy, and all Outboard Marine Comnpany (OMC) products would spec out and at one point, specifically, they wrote not to run "unleaded" fuels.

    Running white gas in two strokes made them burn cleaner and hotter, and when we pulled heads off engines that came into our shop for tune ups, there were no carbon deposits like people who ran leaded fuels.

    Then unleaded became the only thing we can get after the EPA thoughtlessly rewrote how gas can be forumulated to meet thier pollution requirements.

    We run any octane we can find, but many manufacturers recommend 89 or higher. I have not physically seen of felt a difference and not running 89 or higher is nothing to stress out over.
  5. barnard

    barnard LawnSite Senior Member
    Messages: 618

    White gas is unleaded. 87 octane is fine.
  6. barnard

    barnard LawnSite Senior Member
    Messages: 618

    One added note-- unleaded fuel is the best thing to happen in terms of spark plug life. Leaded fuel would build up lead (a metal and a conductor)on the insulator of the plug and cause misfiring.I 've been working on two strokes for 34 years.
  7. PLM-1

    PLM-1 LawnSite Bronze Member
    Messages: 1,640

    my shindaiwa dealer told me always run 91 because of the higher rpm's and compression...i've run 87 and can't tell a difference.
  8. logorhea

    logorhea LawnSite Member
    Messages: 17

    I always used 87 octane, but I just went to Stihl's website and they do call for 89. I then found the latest Stihl owner's manual I have, copyrighted 2000, and it says "minimum octane rating 90 ROZ (U.S.A./Canada: pump octane min. 89!)." The exclamation point is in the manual. I see at that the Europeans are concerned about recent changes in refining methods that are causing problems with high-powered automobiles, so that may be the reason for the "!". The more sulfur they take out of fuel, the less stable it becomes; the new diesel recomendations are for storage less than 3 months, where it used to be a year. I guess I'll get 89 octane.

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