Question

Ignition check during engine runup indicates excessive RPM drop during operation on the right magneto. The major portion of the RPM loss occurs rapidly after switching to the right magneto position (fast drop). The most likely cause is ?

Answer 1

The most likely cause of the rapid drop in RPM when switching to the right magneto position during engine runup could be a faulty spark plug, ignition timing issue, or a malfunctioning magneto. The right magneto may not be generating enough spark to ignite the fuel-air mixture properly, leading to a sudden decrease in engine speed.

Step-by-step explanation:

The most likely cause of the rapid drop in RPM when switching to the right magneto position during engine runup is a faulty spark plug on the right magneto. A faulty spark plug can cause incomplete combustion of fuel, resulting in a rapid drop in RPM. Another possible cause could be a problem with the ignition timing on the right magneto.

Incorrect ignition timing can lead to inefficient combustion and a faster drop in RPM. Lastly, a malfunctioning magneto itself could also cause the rapid drop in RPM. The right magneto may not be generating enough spark to ignite the fuel-air mixture properly, leading to a sudden decrease in engine speed.