In what position should the ignition switch be placed when using a timing light on the magnetos?

In what position should the ignition switch be placed when using a timing light on the magnetos?

• A. On
• B. Neutral
• C. Both
• D. Off

Answer: (C)

To time magnetos with a timing light, the ignition system must be energized so a spark is produced and you can observe the timing marks. Set the ignition switch so that both magnetos are powered. This ensures that as the engine turns, sparks are being generated from both magnetos and the timing light can give an accurate reference. If the switch is off, there’s no spark and nothing to time; if it’s in a single-magneto position, only one magneto would spark, which can give an unreliable or misleading timing reading. Energizing both magnetos provides the proper, consistent reference needed for accurate timing checks.

To time magnetos with a timing light, the ignition system must be energized so a spark is produced and you can observe the timing marks. Set the ignition switch so that both magnetos are powered. This ensures that as the engine turns, sparks are being generated from both magnetos and the timing light can give an accurate reference. If the switch is off, there’s no spark and nothing to time; if it’s in a single-magneto position, only one magneto would spark, which can give an unreliable or misleading timing reading. Energizing both magnetos provides the proper, consistent reference needed for accurate timing checks.