I discovered a problem with my mag nr1 during idle. When carrying out a mag check during idle, mag 1 circuit fails, engine cuts. Checking mag 2 at idle, engine runs.

Normal mag check at 3000 rpm, both mags act normal, with rpm drop of about 80 rpm on both. How can I confirm the health of the two ignition circuits?

The problem is only on idle. The two coils have already been swopped. Any advice will be appreciated.

  • Re: 582 blue top bad mag.

    by » 6 months ago

    Hi Andries,

    The ignition testing process and values are quoted in the Rotax manuals. If that testing yields no definitive results you may want to try this.

    I would verify ignition spark output at cranking speed.

    My homemade spark tester uses four spark plugs mounted in threaded holes on an aluminum strap. A ground path is provided through a wire from the engine block to the aluminum strap. Stay well clear of the propeller and watch for a good spark on the test spark plugs while cranking. 

    If you notice less spark or no spark on both plugs from the same coil, I'd confirm that coils trigger is gapped to specification. If the trigger for some reason is gapped too wide, a higher rpm would be required to properly trigger that coil. 

    Best regards, John 



  • Re: 582 blue top bad mag.

    by » 3 months ago

    Thank you for the sound advice John, will carry out this test and reply with results.



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