Which circuit delivers the spark to the spark plug in a magneto system?

• A. Secondary electrical circuit.
• B. Primary electrical circuit.
• C. Magnetic circuit.
• D. Ground circuit.

Answer: (A)

The spark is delivered by the high-tension, secondary electrical circuit. In a magneto, the primary circuit builds up the magnetic field and stores energy, and when the field collapses, the rapid change induces a high voltage in the secondary winding. That high voltage is carried through the spark plug wire to the spark plug, where it jumps the gap and creates the spark. The ground path helps complete the circuit back to the engine, but the spark itself comes from the secondary winding. The magnetic circuit handles the flux, and the primary circuit controls energizing that flux.