Question 3
- What is meant by ignition timing being advanced?
- List; (i)Two types of ignition system; (ii)Five ignition system components.
- Why is it necessary for the timing to advance when the engine runs faster?
Observation
The expected answers were;
- Definition of advance ignition timing
- (i) Types of ignition system
- Reasons for advancing ignition timing
Ignition timing is the setting of the point at which the sparking fires relative to where the piston is in the cylinder. The highest point the piston can go is called Top Dead Center (TDC), timing is set for number of degrees of crankshaft rotation before the TDC. The number of degrees is determined by the factory, and since it’s setting the plug to fire before TDC, it is called the timing advance.
(a)Contact breaker/conventional ignition system (b)Electronic /transistorized ignition system (c)Programmed/computerized ignition system (d)Direct ignition system (e)Magneto ignition system
(ii) Ignition system components
(a) Distributor cover (b)Ignition switch/key (c)High Tension Lead (d)Battery (e) Coil (f) Spark plug (g) Cable/conductor (h) Ignition fuse (i) Carbon rod/brushes (j) Condenser (k)Contact set/ breaker point (l)Rotor (m)Resistor
The candidates were expected to explain advance ignition timing, list two types of ignition system, and five components of ignition system. State why timing is to be advanced as the engine runs faster.
The candidates’ performance was reported to be average in this question.