Need help understanding my wiring diagram
Thank you for taking time to help me understand a bit more how my mower wiring works. I have a Murray model 42544x8B with a Briggs engine model 28E707-0121-E1 code 9802112E. The wiring diagram is attached below. I have many questions, but let's start with the following:
1) I understand from reading other posts that 12VDC travels from the + terminal of the battery to a terminal post on the starter solenoid. A control wire travels from the ignition switch to the starter solenoid and signals the starter solenoid to transfer 12VDC to the starter which should crank the engine. Please correct me if anything I state is not correct. I really want to understand this stuff.
2) The cranking engine turns the flywheel magnets past the magneto, which should generate a spark at the spark plug. From a mownie post I understand that the "Briggs magneto ignition system uses a completely self contained spark ignition system that DOES NOT use any external source of power." The post also states "To kill a Briggs engine spark (and that kills the engine), you must GROUND the coil kill wire circuit."
My first question is to understand in more detail the kill wire circuit. In my wiring diagram I see a wire leaving the ignition switch terminal 4 (hard to see in diagram - this is the top wire @ 12 o'clock position, labeled YELLOW). This wire travels into a connector and then over to the magneto. I also see what looks like a wire from the magneto to ground. How do these wires cause the magneto to kill the spark?