FAA Powerplant Written Practice Test

In which position should the ignition switch be during the timing of a magneto to the engine?

1. In the left position

2. In the right position

3. Off

4. Both

The correct answer is: Both

The ignition switch should be in the "both" position during the timing of a magneto to the engine to ensure that both magnetos are functioning and can be tested simultaneously. This position allows each magneto to send a spark to the engine, which is crucial for checking the timing and overall operation of the ignition system. When both magnetos are operational, it ensures that any discrepancies in timing between the two magnetos can be accurately assessed, which helps in making necessary adjustments to achieve optimal engine performance. When checking magneto timing, it’s important to verify the timing of each magneto independently as well, but doing so while they are both engaged ensures a comprehensive examination of the ignition system's performance.