KCSE 2012 Power Mechanics Paper 2 with Marking Scheme

STATION 1

In the space below, sketch in good proportion an exploded drawing of a connecting rod assembly. Lable four parts. (10 marks)

STATION 2

Using the tools, materials and equipment provided, make the template shown in figure 1 below. (10 marks)

STATION 3

Identify the parts labelled M, N, O, P and Q and name the motor vehicle system in which each is used. For each part, identify one defect and state its effect on vehicle performance. Complete the table below.   (10 marks)

STATION 4

On the single cylinder provided, determine the big-end bearing clearance at a torque of 25kN/m²

Let the examiner check your work.   (10 marks)

STATION 5

Dismantle the oil pump provided. Measure and record the following:

1. rotor-body clearance
2. tip clearance

Reassemble the pump and test it for functionality.

Let the examiner check your work.   (10 marks)

STATION 6

On the drum brake of the vehicle provided:

1. remove the return spring. 
2. measure the tension of the spring. 
3. replace the return spring

Let the examiner check your work.   (10 marks)

STATION 7

Using the tools, materials and components provided, connect a three-lamp lighting circuit such that two lamps are in series while the third lamp is in parallel.

Let the examiner check your work.  (10 marks)

STATION 8

On the vehicle provided

1. identify the parts labelled X, Y and Z.   (3 marks)
2. determine the toe-in of the vehicle.   (7 marks)

Let the examiner check your work.

STATION 9

Using the tools and materials provided, mend the hole marked on the tube.

Let the examiner check your work.      (10 marks)

STATION 10

On the multicylinder engine provided, carry out the following tasks:

1. check and comment on the condition of the spark plug for cylinder number 3.      (3½marks)
2. service the spark plug.

Let the examiner check your work.    (6½ marks)