Stihl FC-75 dies ???

Discussion in 'Mechanic and Repair' started by eZrider, Jul 10, 2006.

  1. eZrider

    eZrider LawnSite Member
    from Georgia
    Posts: 25

    My FC-75 edger has been acting weird. Sometimes it will just shut off and nothing I know to do will get it restarted. I will let it sit all night with plans on taking it to the dealer the next morning and it always starts on the second pull. Any idea what could be causing this?
     
  2. MowerMedic77

    MowerMedic77 LawnSite Bronze Member
    Posts: 1,164

    Ignition Coil, Sthil is notorious for coil failures.
     
  3. eZrider

    eZrider LawnSite Member
    from Georgia
    Posts: 25

    I wondered if that might be the problem but I thought when a coil went bad, it was bad. I have never known one to be intermittent. I will try that tomorrow, thanks for the help.
     
  4. ed2hess

    ed2hess LawnSite Fanatic
    Posts: 13,328

    Had one on a Echo that acted same way....works for a few hours then failed and worked again next day.
     
  5. MowerMedic77

    MowerMedic77 LawnSite Bronze Member
    Posts: 1,164

    If you are going to install it yourself be sure and fallow the directions that come with the coil put the plastic spacers in correct position and be sure to use a business card between the magnets on the flywheel and the coil to set your air gap.
     
  6. eZrider

    eZrider LawnSite Member
    from Georgia
    Posts: 25

    It sounds like that must be the problem. I will pick up a new coil in the morning. Thanks for the help guys!
     
  7. FIXDISS

    FIXDISS LawnSite Senior Member
    Posts: 445

    They work til they get hot then fail.
     
  8. Jim@MilkyWay

    Jim@MilkyWay LawnSite Senior Member
    Posts: 472

    I can give you an idea of how a coil could be intermittent.
    I have seen the same effect even with something as common as a light bulb. When the temperature of _anything_ ( with the exception of diamond, VERY PURE DIAMOND )changes, there is this consideration called " the coefficient of expansion". To give you an idea how important this effect can be, check with a bridge engineer.
    Long story short, When a wire breaks, literally, inside of a coil, depending on where that break is, the "gap" can expand or contract, again _depending on the temperature change and where the break/gap is_. If the gap expands, it opens up even more, and the coil dies; if it contracts, it closes, thereby making electrical contact. LONG LIVE THE COIL! Does that make any sense, at all??
     

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