early style Stihl FS80 trimmer carb acting up

Discussion in 'Mechanic and Repair' started by Jim HIJKL, May 27, 2008.

  1. Jim HIJKL

    Jim HIJKL LawnSite Member
    Posts: 2

    Hello folks, I have an early style Stihl FS80 with the slide-type carb. I've not had a lick of trouble with in the 20+ years I've used it, until now. Compression and spark are still plenty good but carb is acting up. I've replaced fuel lines & tank filter and checked primer bulb - all good now. My carb is the one with all three adj screws in line with the slide - it's a TK I think. The screw toward the top of the slide barrel is the idle screw but I've lost my manual and can't remember which screw is high and which is low speed jet. It acts like the adjustment needles are worn but I don't want to take it apart until I can find a kit. Does anyone know what this carb is for sure and where I can find a kit? I'll also need the correct adjustment procedures. Thanks for your help. Jim
     
  2. scottr 2006

    scottr 2006 LawnSite Member
    from alabama
    Posts: 70

    Jim, the screw next to the idle screw is the low speed adjustment screw. The basic adjustment for the L is 1 turn ccw from lightly seated. The basic adjustment for the H is 2 turns ccw from lightly seated.
     
  3. Jim HIJKL

    Jim HIJKL LawnSite Member
    Posts: 2

    Thank you Scott. I think the main problem was the o-ring seal on the hi needle. It was hard and brittle allowing the needle to rotate on its own. I sized a new o-ring off the bore and stem diameters so will try it after replacing the starter rope.
     
  4. scottr 2006

    scottr 2006 LawnSite Member
    from alabama
    Posts: 70

    Jim, not long ago a guy on arboristsite had a thread about using a aftermarket kit on his old FS80. If you want his name send me a message.
     

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