I'd forgotten about rust being an issue. Odd thing is that we have one dead mower right now (ignition) and the coil laminations are rusty as the dickens - so is the flywheel magnet.Some thing that I have found for a no spark condition-- Rust on the coil laminations and on the magnets themselves. Clean the rust off and reset the coil to magnet gap at around 0.010- 0.015 inches, (two sheets of printer paper) and your good to go.
Never seen that with a points style ignition. The new style electronic though would have one.that second wire should have a diode in line and go to ground.
The small engine electronic ignition modules that I've seen still use the original coil from the engine. The original coil makes both the low and high voltages for the ignition.>snip<
I'm starting to think I should convert this to an electronic ignition, that costs about $20.00....
Thanks,
Gary