Question

During your live mag check, you switch the mags from both to left and the RPM drops by 100. You then switch the mags from both to right and there is no change. Which mag is not working properly?

a) Both
b) Left
c) Right
d) None

Answer 1

The left magneto is likely not functioning properly, as evidenced by a 100 RPM drop when switching from both to left, whereas there was no drop when switching to right

Step-by-step explanation:

During the live mag check, when you switch the mags from both to left and the RPM drops by 100, but there is no change when you switch from both to right, this indicates a potential problem with the left magneto. Normally, there should be a slight RPM drop when switching from both to a single magneto as the engine is running on one magneto instead of two, but a drop of 100 RPM is significant and typically indicates that the corresponding magneto is not functioning properly. In this case, because there was no RPM drop when switched to the right magneto, the right magneto is likely functioning as it should. Hence, the correct answer is (b) Left.