Tuning a 2 cycle carb

Discussion in 'Mechanic and Repair' started by Guido, Sep 19, 2002.

  1. Guido

    Guido LawnSite Silver Member
    Posts: 2,085

    Anyone want to give me a quick lesson on tuning a 2 cycle carb. I'm not as dumb as I sound sometime, I have some mechanical knowledge. I know you have your 2 screws, one for air and one for fuel, right?

    I remember someone trying to teach me once telling me to tighten them down and then 3/4 of a turn...I dunno, something good to start with. How do I tell which one is which?

    Please help me out when you get a minute, its no rush.

    Thanks!
     
  2. khouse

    khouse LawnSite Bronze Member
    Posts: 1,465

    one low (L) needle that's for idle and some midrange
    one high (L) needle that's for upper mid and full throttle.
    start with both needles at 1 turn out from seated.
    start with the low needle with the engine at idle.
    open the needle up until it starts to sputter make visual note of needle position
    turn the needle in past where it runs good untill it sputters. make visual note of needle.
    put needle in the middle of these two visual positions.
    set idle speed screw for idle speed.
    after idle speed is adjusted do this all over again untin it idles just right.

    then adjust high speed the same way but with it running wide open while adjusting.

    good luck
     

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