Stihl backpack blower?

Discussion in 'Homeowner Assistance Forum' started by jscozz, Apr 5, 2013.

  1. Valk

    Valk LawnSite Silver Member
    Messages: 2,760

  2. jscozz

    jscozz LawnSite Member
    Messages: 48

    Picked up a 600 today! Blowing leaves has never been so much fun!

    This thing is great! Thanks for all the advice and feedback! Much appreciated!

    THIESSENS TLC LawnSite Senior Member
    Messages: 892

    Ya your gona love it more n more everytime ya use it! Lol.
    Posted via Mobile Device
  4. rlitman

    rlitman LawnSite Bronze Member
    Messages: 1,763

    The smell of gas is not from the burned oil in the fuel, but instead is from unburned gasoline. 2-cycle engines do not have valves, and by their very nature will send some unburned fuel out the exhaust port.

    4-cycle engines burn their fuel much more completely because the valves maintain pressure in the cylinder until combustion is complete, and there is almost no unburned gasoline left when the valves finally open. Sure, there is smoke from the burned oil, but that doesn't smell nearly as much as the unburned fuel itself.
  5. rlitman

    rlitman LawnSite Bronze Member
    Messages: 1,763

    edit: whoops, double post
  6. avguy

    avguy LawnSite Senior Member
    Messages: 565

    Congrats! I love mine.
  7. Valk

    Valk LawnSite Silver Member
    Messages: 2,760

    Thank you for your explanation. I was not correctly thinking about this unburned fuel aspect...just focusing on the oil.
  8. rlitman

    rlitman LawnSite Bronze Member
    Messages: 1,763

    Sure. 15 minutes of edging my property with my FC-85 2-cycle, and my wife won't let me back in the house without switching shirts because I smell like gas. Same thing when I had a BG-85, or MM-55, or any other 2-cycle equipment I had in the past.

    Never had that issue with 4-mix stuff. At 50:1, there isn't much oil anyway, and the synthetic stuff doesn't seem to smoke much (and you need to use synthetic with the 4-mix machines). I can use my BR500 or KM110 for hours on end, and I'll only smell like sweat. :)

    Now on my Seagull outboard engine that wants 10:1 mix, yeah, the oil smoke sure comes into play.
  9. Valk

    Valk LawnSite Silver Member
    Messages: 2,760

    Gosh, I HATE my 2-stroke hedge-trimmer just because I STINK after using it.
    Guessing Stihl makes a 4-mix version...hmmmm. :germanflag:
  10. rlitman

    rlitman LawnSite Bronze Member
    Messages: 1,763

    I can see it being worse with a hedge trimmer, or if you're using a string trimmer left handed.

    My string trimmer's exhaust points away from me (out to the right), but with a hedge trimmer in front of you (and being used in all sorts of orientations), you're sure to catch more of the exhaust on your clothing. I know that when I use my kerosene torpedo heater, the smell gets in my hair like it is magnetically attracted to it. I remember 2-cycle machines giving me the same issue. My BG-85 especially (because I used it as a vacuum, so it was always in front of me, and exhausting towards me too).

    I don't think Stihl's regular hedge trimmers are 4-mix though. My hedge trimmer is the one that fits on my Kombi, and that is 4-mix.
    I'm quite happy with that. The extended trimmer lets me reach everything easily, and the blades are always out of my reach too.

    Honestly, after hearing good things about their new EFI saw, I'm waiting to see if they release a 4-mix EFI replacement for the SH-86. That'll be my next machine.

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