Fastest Way to Check a Coil (Magneto) on Older Small Engines

Fastest way to rule out if your no spark condition is due to a bad coil or magneto or if you have other problems.

[@leonardfoster6252]

You check it correct, 3 ways to check it...

[@frankdavidson9675]

the plug wire does not go to the mounting that you are testing it goes to the seconary winding --------as the magnet on the fly wheel spins by the coil it creates a voltage in the primary winding now due to the turns ratio primary to secondary coils a high voltage is created due magnetic effect which then the high voltage goes to spark plug -- make sure magnet is good on the flywheel it will grab a screwdriver thats a good magnet sub a coil off a running eng . if you get a spark with a diff coil that tells you ----you need a coil good luck hope this helps.

[@daveschidlmeier6425]

Your absolutely correct Frank. He should sand the rust off the magnets and the coil, remount the coil with ten thousands clearance between it and the magnets on the flywheel.
The way he tested the coil was useless. Just saying.

[@Rein_Ciarfella]

@@daveschidlmeier6425 Actually, cleaning rust off air gap surfaces is only necessary when setting the air gap because rust will change that gap so anything used to measure or set the gap will be increased. Rust in itself will still allow a magnetic pulse and allow the magneto to produce an electrical charge. That said, cleaning the mounting surfaces of the magneto and the machine will ensure a good ground because rust does inhibit an electrical connection.

[@daveschidlmeier6425]

@@Rein_Ciarfella that is why I would clean the rust off off the flywheel magnets and coil, to get the proper clearance between the two units. Otherwise the clearance would be larger if the rust was left on.