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100 octane gas will "burn up" saw???

Discussion in 'Chainsaw' started by Plasmech, Mar 9, 2009.

  1. Plasmech

    Plasmech Addicted to ArboristSite

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    I've got a landscaper guy telling me that the 100 octane "jet fuel" that I'm running will burn up my saws. I don't understand how this could be, but I wanted to run it by you guys just to be safe. The only reason I buy 100 is to get actual gasoline and not ethanol. Is there any way excessive octane could hurt an engine? I mean the answer has to be "no" right?

    (By the way, I didn't bother to explain to this guy that Jet A is nothing more than glorified kerosene)
     
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  2. blsnelling

    blsnelling Site Sponsor

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    First of all it's not jet fuel. And it will not burn up your saw. Lots of guys use it.
     
  3. clutch25

    clutch25 ArboristSite Operative

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    I'm with Brad! :agree2:
     
  4. ShoerFast

    ShoerFast Tree Freak

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    100LL is avation gas for lower (then the real hi-performance) performance engines.

    We ran kerosene instead of Jet 'A' , but a gas engine will not run on it, pictures is a J-85 Jet engine at 75% full AB on kerosene.

    [​IMG]
     
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  5. Crofter

    Crofter Addicted to ArboristSite

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    Tell him he is correct but you had your saws ceramic coated inside!:)
     
  6. tree MDS

    tree MDS Daddy

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    The higher octane actually burns slower than say "regular" gas.

    Thats how they avoid preignition in higher compression race style motors.

    Its a common misconception.

    I would think it would be fine - but not necessary. I run 93 in my saws.
     
  7. Buckethead

    Buckethead ArboristSite Operative

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    You are obviously a smart man and don't need us to tell you that your landscaper guy is smoking his clippings. I know you're smart because you belong to AS and you run 100LL in your saws. Also you didn't bother to waste your breath explaining the whole Jet-A vs. Kerosene thing to him.

    All the guys that have responded are correct as usual.:cheers:

    I am constantly amazed at the misconception that lots of people have about avgas and jet fuel. I've lost track of how many times I've explained it to guys who are amazed at the explanation.

    So, add me to your list of supporters...I know I'm in good company.

    Hey..how about telling your landscaper that you're now running your saws on hydrazine and liquid oxygen...but you had to tweak the flux capacitor for optimal performance!
     
  8. Jesse Benson

    Jesse Benson ArboristSite Lurker

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    The saw will actually run cooler and cleaner on AV gas.
     
  9. blsnelling

    blsnelling Site Sponsor

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    And slower.
     
  10. mattmc2003

    mattmc2003 Addicted to ArboristSite

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    Why slower?
     
  11. tlandrum

    tlandrum Sponsor/ Saw Builder/husqvarna ,jonsered dealer

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    I'd have to agree that it will run cooler
     
  12. tomtrees58

    tomtrees58 Addicted to ArboristSite

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    :agree2:tom trees :cheers:
     
  13. Woodie

    Woodie "Cap'n Bullcrap'n"

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    I'd love to try avgas, but it's the LL part that keeps me from doing it.

    Does anyone know if avgas (not Jet A) is available without the lead?



    .
     
  14. Photog95

    Photog95 ArboristSite Operative

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    Back in the 70' and 80's people would run out in droves to the airport to get fuel for the weekend at the drag strip for better performance. When we got old enough to get our drivers licence we went get some for our MX bikes. The dude at the airport said it was not a good idea to run it in a 2 stroke engine because it was a very dry fuel. He said if we must try it we should mix in plenty of extra oil to make up for it.

    I have no idea if the guy was right or not because we decided on the side of caution because we werea bunch of punk azz high school jobless fooks and couldn't aford engine failure.
     
  15. oldsaw

    oldsaw "Been There, Milled That"

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    And better shelf life
     
  16. Jesse Benson

    Jesse Benson ArboristSite Lurker

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    I am not a mechanic or anything but I would have to argue Av gas making them slower. Why would they run high octane fuel in race bikes (motocross), atleast they did before the 4 stroke era. If they can design $100,000 race bikes, I doubt they are lacking the knowlege about proper fuel.:cheers:
     
  17. Nitroman

    Nitroman Addicted to ArboristSite

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    Tetra-ethyl lead has been used in gasoline since the early teens to prevent knocking, no, the avgas won't "hurt" you. It was in virtually all gasolines up until 1985, so the hysterical hair-pulling occasionally seen here can be ignored.

    Avgas is no more "dry" (what the h**l is that anyway?), than any other gas.

    I would love to see a dyno sheet with a engine run on regular and then avgas to see if it was "slow" or "lost power". Haven't seen one yet, but have seen many comments on this.
     
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  18. Jesse Benson

    Jesse Benson ArboristSite Lurker

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    Check your local motorsports shop. They usually sell VP race gas, I think it is 104 octane, comes in 5 gal steel jugs. It smells good to, the exhaust that is.:greenchainsaw:
     
  19. PA Plumber

    PA Plumber Addicted to ArboristSite

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    Slower = Richer?

    Been running 100LL for a while now. Can't remember if I richened or leaned out the carb when I switched.
     
  20. blsnelling

    blsnelling Site Sponsor

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    I have found 100LL to make my saws run slower and have had this confirmed by another engine builder respected here by most everyone. I'm not going to pretend to know more than I do here, but I'll take a stab at it.

    High compression engines require the higher octane or burn up the engine due to pre-ignition. The high octane fuel is not making this power, it's just allowing the engine to run as it should without damage. Your typical stock or woods ported saw does not need this octane. Higher octane fuel burns cooler and slower. Your saw doesn't need this and as a result runs slower.
     

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