Powerplant - AM.III.H.K2 - Spark plug theory

Question 1

what is the function of the capacitor in a magneto?

Answer 1

the capacitor minimises arcing at the breaker points, and it speeds up the collapse of the primary current as the breaker points open

Question 2

what happens in a magneto ignition system when the ignition switch is placed in the off position?

Answer 2

the primary current is connected to gorund

Question 3

what is checked when a magneto is internally timed?

Answer 3

• internally timing a magneto consists of adjusting the breaker points so they will open at the instant the rotating magnet is in its e gap position
• and the distributor rotor is in position to direct the high voltage to cylinder number 1

Question 4

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

Answer 4

in the both position

Question 5

What is the e gap in magneto timing?

Answer 5

• the e gap is the position of the rotating magnet where the primary current flowing in the magneto coil is the greatest
• the breaker points open when the rotating magnet is in its e gap position

Question 6

what malfunction in the ignition system would cause an aircraft reciprocating engine to continue to run after the ignition switch is places in the off position?

Answer 6

the ignition switch is not grounding the primary circuit