Originally Posted by jasonh

Magnetos output AC.

Yes, they are called CDI's as in capacitor-discharge-ignition. My beef currently is I cannot find anything about a real CDI that only has 2 wires. Everything I can find basically says this:

A CDI will take a constant power source and keep a charge inside. Then it gets a pulse signal from the motor and releases all that energy into the coil which then steps up the voltage big time and that gets output to the plug which has your lovely little spark.

We only have a power and ground on these, so I don't see how exactly they would work short of just acting like a normal coil and sending out a zap every time the magneto spins around and makes a pulse o' power.

Not to mention, how are these "CDI's" so darn cheap? I can't find cheap Chinese CDI's for under $50-75.

Originally Posted by jasonh

Right now I'm actually wondering it basically charges on the + pulse from the magneto, and then the - signal from the magneto is the extra "trigger" pulse. That seems like it could be logical, but I can't seem to find any info on anything similar.

Any ideas on what kind of ignition mowers use?

Originally Posted by jasonh

So I've been Googling like mad, and I think I may be on to something. It kind of looks like our ignition system is similar to the Briggs Magnetron system, but the trigger coil is our magneto. Which brings me around full circle wondering why the heck this test doesn't work. Some info on the Magnetron system:

The Magnetron Ignition System - Learning Activity
Timing is Everything - Basic Kart Ignition Explained, Part 2 - Article by John Copeland (first half of article)