AMT Reciprocating Engine Ignition Systems 3

Question 1

What does the term 'magneto timing' refer to in the context of reciprocating engine maintenance?

Accepted Answer

The relationship between when the breaker points open and piston position

Answer

Magneto timing establishes the crankshaft position (in degrees before TDC) at which the points open and the spark fires, directly affecting engine power and efficiency.

Question 2

Spark plug reach is defined as:

Accepted Answer

The length of the threaded portion that protrudes into the combustion chamber

Answer

Spark plug reach is the length of the threaded section; incorrect reach can cause the plug to sit too deep or protrude too far into the cylinder.

Question 3

A high-tension ignition harness that shows carbon tracking would most likely cause:

Accepted Answer

Intermittent misfiring or cross-firing between cylinders

Answer

Carbon tracks provide a low-resistance path for high-voltage current to leak to ground or to adjacent leads, causing misfires or firing the wrong cylinder.

Question 4

When checking breaker point condition on a magneto, points that appear blue or burned indicate:

Accepted Answer

A faulty condenser allowing arcing across the points

Answer

A defective condenser fails to absorb the collapsing magnetic field energy, causing arcing at the breaker points that burns and erodes them.

Question 5

The distributor in a high-tension magneto system serves to:

Accepted Answer

Route the high-voltage output to each spark plug in firing order

Answer

The distributor receives high-voltage pulses from the secondary coil and directs each pulse to the correct spark plug at the proper time in the firing sequence.

(AMT) Aviation Maintenance Technician Practice Test

(AMT) Aviation Maintenance Technician Practice Test

AMT Reciprocating Engine Ignition Systems 3