AMP - Aviation Maintenance Technician Powerplant Practice Exam

When a magneto is operating, what is the probable cause for a shift in internal timing?

1. The rotating magnet loses its magnetism.

2. The distributor gear teeth are wearing on the rotor gear teeth.

3. The cam follower wear and/or the breaker points wear.

4. Magnetic flux inconsistency

The correct answer is: The cam follower wear and/or the breaker points wear.

When a magneto is operating, a common cause for a shift in internal timing is wear on the cam follower and/or the breaker points. This can result in the timing becoming inaccurate, leading to a shift in internal timing. The other options are incorrect because they do not directly relate to the functioning of a magneto, and therefore would not be considered probable causes for a shift in internal timing. Option A is incorrect because the rotating magnet losing its magnetism would not affect the timing mechanism. Option B is incorrect because it refers to the distributor and rotor, which are not part of a magneto. Option D is incorrect because it does not specifically address the functioning of a magneto or its timing mechanism.