I have an old dresser lawn tractor. It was running when I parked it last fall. Now it cranks but won't start. I can't detect any spark. I removed the kill wire from the magneto & jumped the solenoid; spins, but still no spark. There are interlocks on the mower engage lever, but the clutch & seat interlock systems have been disabled. I thought that removing the kill wire from the magneto would enable me to by-pass all the interlocks & start the engine. The engine model is 422707; type 1208 02; code 88013012.
What is the proper method for testing magneto output?

Removing the kill wire only controls the killing of the fire at the magneto itself.

There is a terminal mounted on the engine housing. There is a wire that comes out from the magneto to that terminal. There is another wire that runs from that terminal to the "ignition switch" on the dashboard. It is my understanding that grounding that terminal kills the ignition. That is what the "ignition switch" on the dashboard does. That is essentailly what all the safety interlocks do. I attempted to reliably un-ground the magneto to see if it will produce a spark. I know that if the engine had started, the only way to shut it off would have been to ground that terminal.
All this is theoretical; what I seek is confirmation that my theory is correct, or that I am like, way wrong. Comment?