Trimmer Trouble

Discussion in 'Mechanic and Repair' started by jmurphy, Apr 16, 2006.

  1. jmurphy

    jmurphy LawnSite Senior Member
    Posts: 273

    :clapping: I have a straight shaft Toro trimmer that isnt working properly. It will start and idle, but if i give it any throttle it will throttle up then just die out and shut off. What could be causing this? Bad fuel line?Spark arrestor? Any help appreciated. By the way, Happy Easter!!!!
  2. oldrustycars

    oldrustycars LawnSite Senior Member
    Posts: 301

    just yesterday i went through some Stihl machines with ths exact problem. the fuel lines were like overcooked pasta. i replaced all fuel lines, rebuilt the carbs, and they run like scalded dogs now. i suspect just the fuel line would have fixed the trouble, but i dont like comebacks, and the owner of these wants them to work all season for him.
  3. Partsangel

    Partsangel LawnSite Member
    Posts: 80

    and If your fuel lines and tank filter are in good shape you can try to adjust the carb needles(if it has any) if you have a H and L marked on your carb try opening the L about a half of a turn Counter Clockwise. then retry.

    Mike AKA Partsangel
  4. Lawn Masters

    Lawn Masters LawnSite Senior Member
    Posts: 850

    I'd pull the spark arrestor first and then check everything else.
  5. lawnmaniac883

    lawnmaniac883 LawnSite Silver Member
    Posts: 2,613

    Sounds like a carb in need of rebuild to me.
  6. jud149

    jud149 LawnSite Member
    Posts: 102

    I just went thru this (twice) with my Echo prunner. The first time it was the spark arrester and the second time it was the carb. A new kit for the carb fixed it the last time.
  7. dutch1

    dutch1 LawnSite Silver Member
    from Jayhawk
    Posts: 2,231

    Depending on hours on the equipment the two most common failures are varnished up fuel filters and plugged exhausts(ports and spark screens). Two cycle equipment should be run at full throttle most of the time. I have had innumerable pieces that were run at low speeds that had plugged ports/screens due to incomplete combustion which contribute to high carbon buildup. Carbs just don't get out of adjustment that frequently unless they develop weak diagphrams over a period of time.

  8. Partsangel

    Partsangel LawnSite Member
    Posts: 80

    Â…Running a two cycle engine at full throttle is a must 90% of the time, of course the lawn keepers will need to idle down occasionally near close areas etcÂ…. Spark arrestors are always something you need to keep your eye on, but to get back on topic a two cycle that will start and idle then when you give it the gas/throttle and it hesitates or dies, the problem lies in the transitional fuel circuit aka low Idle adjustment. The transitional fuel circuit acts like a accelerator fuel pump on old float style auto carbs, it holds enough fuel in the carb to make the transition from idle to high speed. Two cycle carburetors in general..past or present have either got a H and L adjustment or just a L adjustment or they are preset at the factory aka no adjustment Nada. If your two cycle flattens out/hesitates/dies when you give it the gas a minor carb adjustment can save you from going to the shop at least for another season. :)


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