Starting And Ignition

Question 1

Engine fly wheel gear.

Answer 1

Helps smooth out the engines power delivery by strong rotational energy.

Question 2

Starter warning/operating light.

Answer 2

If light is still on after 30 seconds due to starter motor still being on, you have to turn the engine off.
Starter motor still being driven by crankshaft.

Question 3

Auxiliary spark augmentation.

Answer 3

When magneto rotation is slow (during starting), insufficient HT voltage may result.
3 methods of spark augmentation:
Impulse coupling
Low tension booster
High tension booster

Question 4

What is a magneto?

Answer 4

An electrical generator that uses permanent magnets to produce periodic pulses of alternating current. (AC generator)

Impulse starting - A component, helps start engine by providing additional torque.

High tension wires carry current from distributor to spark plug.

Fail safe in air.

Question 5

Magneto checks.

Answer 5

Drop check and dead check.
If either checks fail, engine mist be shut down and fault logged in AML.

Question 6

Drop check.

Answer 6

Carried out twice.
At 1000-1200rpm switch each magneto off; monitor for drop in rpm and change in engine sounds, engine should continue.
If check is ok, increase rpm to 75% or maximum (2000-2200) and perform check again.
Monitor, rpm should drop 100-175rpm.
If rpm drops >400, may have faulty spark plug.
Report in AML.

Question 7

Dead cut.

Answer 7

Ensure ignition switch circuit is working and engine can be shut down electronically.
At 75% max rpm, just after drop check, switch ignition off briefly.
Engine rpm should rapidly decay as magnetos are turned off.
Switch needs to be turned back on before engine can completely stop.

Question 8

How does a sparkplug work?

Answer 8

Body forms electrodes.
At centre electrode, sparks cause it go jump across gap.
gap blocked = fouled

Question 9

What does the capacitor do?

Answer 9

Allows for rapid collapse of field.
Prevents arcing and sparking if breakers too.

When capacitor empties, magnetic field will fall through secondary circuit.
Apart from ignition switch, everything gears inside magneto.

Question 10

Magneto Schematic.

Answer 10

Image in files, 23

Question 11

What does it mean if you turn ignition off and it doesn’t turn off?

Answer 11

Broken p lead