What Octane for 2 Cycle's ?

Discussion in 'Lawn Mowing' started by Mowman, Jul 17, 2001.

  1. Mowman

    Mowman LawnSite Senior Member
    Posts: 553

    What octane do you guy's run in you 2 cycle mowers,trimmers,ect? I took in my Toro Pro-Line 21" for a banging and knocking noise. 2 weeks left on the warrenty. Toro is now telling the dealer that I was running the WRONG fuel in it. I've been running 89 Octane Shell. Still getting excess carbon build up. If Toro does not stand behind this I will never buy anything they sell, Toro, Exmark, ect.
    I think the owners manual says to run 89 octane or higher. What should I do? Pay the bill or FIGHT them, show them the octane rating in the manual? Help me out here guy's as this could take a chunk out of the checkbook.
  2. Eric ELM

    Eric ELM Husband, Father, Friend, Angel
    Posts: 4,831

    I run 87 octane in all my equipment that is gas, 2 and 4 cycle. From what I've read, air cooled gas engines are designed to run on 87 octane, so this is what I've run for 16 years.
  3. mdb landscaping

    mdb landscaping LawnSite Silver Member
    Posts: 2,205

    i use 89octane texaco in my 2 cycle equipment
  4. rixtag

    rixtag LawnSite Senior Member
    from Lehi Ut
    Posts: 280

    I am reminded of a excerpt from my 2 stroke yamaha waverunner owner manual. Basically octane rating is irrelevant when used in a 2 stroke. Something to do with the flame and the oil negates the advantage of higher octane in gas/oil combination. Ever since reading that I have paid no attention to the octane. I buy the same for all equipment and vehicles. Here in UT, 85 octane works like a champ.

  5. Eric ELM

    Eric ELM Husband, Father, Friend, Angel
    Posts: 4,831

    rixtag, 85 octane? The lowest we have here is 87. I have not heard of 85 octane gas before. Are you sure on this?
  6. mowerman90

    mowerman90 LawnSite Bronze Member
    Posts: 1,491

    I read an article years ago about a new trimmer seizing up after only a weeks work. It seems that the owner used reg 87 octane gas in it using the proper oil mix. The problem was caused by the fact that under federal law refineries can mix up to 10% alcohol in their gas blends and do not have to tell you this. Guess what, alcohol doesn't mix with gas!!!! I've always used PREMIUM gas in all my 2 cyl equipment for that reason. Alcohol blended gases cannot achieve 91 octane so you're assured that the premium is alcohol free. I call it cheap insurance, plus my stuff doesn't carbon up nearly as much.
  7. rixtag

    rixtag LawnSite Senior Member
    from Lehi Ut
    Posts: 280

    Eric, I am pretty sure but I will dbl check when I fill up today!

    Mowerman, from Nov to Feb we have oxygenated fuel, up to 25% methanol and that wreaks havoc with 2 strokes. I am lucky because that is right in the middle of the off-season so i don't have to worry but alcohol will tear up a 2 stroke for sure.

  8. roscioli

    roscioli LawnSite Senior Member
    Posts: 749

    I use 87 octane in everything except my honda civic. High compression engines are to be run on high octane. MOWMAN- If it says 89 octane in the book, fight it till your death. Call toro, a head honcho, not some moron, and fight fight fight. mowERman-
    IN mass we are lucky, its a state law that you have to post on the pump if the gas has alcohol in it, and only some cheap companies use it.
  9. Fallguy

    Fallguy LawnSite Member
    Posts: 95

    cleanliness of the fuel i think is more important than what octain fule used (i.g. that no water is in the fuel)- however there are some companies recomend a higher octain and will void your warranty if they find out you used otherwise
  10. Keith

    Keith LawnSite Gold Member
    Posts: 3,977

    I use 87 octane.

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