[asphaltgambler]

I could be wrong, but I'm pretty certain the Growler induces magnetic field - then you test for open / shorts in the armature through the commutator bars as is shown above. I used these as a kid working in a International Tractor dealer to test / repair starters and generators.

I do not know what the life expectancy of magnets in lawn mower flywheels - but its usually the air gap between the coil pickup / magnet that makes it go or no. Make sure each surface has no rust, set the gap as close as possible without touching; ignoring what the manufacturer or your buddy says.

If you follow this, certain the points/ condenser are fresh and set correctly ( obvious) if there is not a strong spark- the likely scenario is the coil assy has failed. Most coils are still available via interwebs.

BTW - a little trick to enhance power / torque is to slot the mounting holes slightly so you can move the coil assy sideways @.015 against the rotation of the flywheel. This advances timing and is really worth the effort.

PM me if you have any questions