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Mag drop

in 912 / 914 Technical Questions 8 years ago
1995 r0tax ,80 hp kitfox runing rough on left mag at low revs ,plugs on number one black all others good,we have done ohhms checkon all electrics moved motor forward to check triger coils all set to 20 thou is that maximum gap ok ,new floats and gaskets in the carbys with fresh balance i have run out of idears can sombody advise me on a fix thanks preston

  • Re: Mag drop

    by » 8 years ago

    The manual says 12-16 thou, or 0.3-0.4mm for the gap. I had a similar sounding problem recently and chased it down to one coil being set at 21 thou. Engine ran fine with 50-75rpm drop at 4000 but rough and a few hundred drop at 3000 or so and below on one side. Cured by resetting to 14 thou. Starting improved too.

    Peter
      
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  • Re: Mag drop

    by » 8 years ago

    Thanks for that i will try that ,its driving me mad they are so good when they are runing well i will let you know how i go preston
      
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  • Re: Mag drop

    by » 8 years ago

    Trigger coil gaps are best set to minimum gap vs maximum gap.

    Roger Lee
    LSRM-A & Rotax Instructor & Rotax IRC
    Tucson, AZ Ryan Airfield (KRYN)
    520-349-7056 Cell

      
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  • Re: Mag drop

    by » 8 years ago

    Other thing to try is switch your ignition boxes see if it fallows the box I had that happen to me this summer did a lot of stuff to fix it and the new mags or ignition boxes fixed it
    Thank you said by: preston boley
      
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