Dan C. May: I'm going to respond in two parts. First, thank you for reading my earlier post. I hope it helped you gain an understanding of how a Magneto works. I found I had to look a few things up myself in order to teach you what I thought I knew.
It's funny, but I stumbled across a section in the Kohler Service Manual for the K-Series which covers the same topic I did below, WITH ILLUSTRATIONS!
I need to read the manual myself!
(If you don't know what RTFM means, ask someone in industry
)
From page 8.1 Kohler Service Manual
[Begin Quote with section header]
Magneto Ignition System Operation
In all magneto ignition systems, high-strength permanent magnets provide the energy for ignition. In rotor type systems, the magnet is pressed onto the crankshaft and is rotated inside a coil-core assembly (stator) mounted to the bearing plate. In other systems, a permanent magnet ring on the inside of the flywheel revolves around the stator. Movement of the magnets past the stator induces electric current flow in the stator coil (and in alternator and lighting coils if provided). The magnets are mounted with alternate North and South poles so that the direction of magnetic flux constantly changes, producing an alternating current (AC) in the stator coil windings. Refer to figure 8-1.
The stator windings are connected to the magneto ignition coil. Current flow in the ignition coil reaches its highest peak at the instant the magnetic flux reverses direction. This is the point at which the system is timed to provide spark at the spark plug.
The ignition coil has a low tension [or voltage] primary winding and a high tension [or voltage] secondary winding. The secondary winding has approximately 100 turns of wire for every turn in the primary. This relationship causes the voltage induced in the secondary windings to be about 100 times higher than in the primary. If the magneto produces 250 volts in the primary winding, the secondary winding voltage will be 25,000 volts.
When ignition is required, the breaker points open to break the primary circuit. The resultant sudden collapse of the field around the the primary winding causes sufficient energy to be produced in the secondary winding to bridge the spark plug gap. The collapsing field also induces energy in the primary winding, but the condensor [capacitor] shunts this energy to ground, preventing it from bridging the breaker point gap. Figure 8-2 shows a typical stator and coil assembly.
[End Quote]
The text goes on to describe how to set the timing on a magneto ignition, as well as describing how the other two (2) types of ignition work on a Kohler motor, namely, the Battery Ignition and the Breakerless (Electronic) Ignition System.