Mechanical Test Flashcards
1
Q
where are the water jackets located?
A
around the cylinders
2
Q
at what point is the petrol mixed with air before being drawn into the engine?
A
in the venturi
3
Q
how do the engine’s pistons move?
A
up and down
in and out
4
Q
what changes the movements of the pistons to rotary motion?
A
the crankshaft
5
Q
what is the air cleaner fitted to?
A
the air intake
6
Q
which of the following would make the engine difficult to start?
A
choices : 1. poor water circulation … 2. the compression is very poor…
3. the coil is hot…4. no oil in the crankcase
answer: the compression is very poor
7
Q
what are the most likely causes of overheating?
A
- poor water circulation
- binding brakes
- broken fan belts
- ignition sparks too retarded.
8
Q
when an engine is said to be missing
what does this mean?
A
one of the cylinders is at faulty
9
Q
what is the prime use of the carburetter?
A
to mix petrol with air
10
Q
what can cause flooding in the carburetter?
A
- float stuck in down position
- float is too heavy
- needle valve stuck in open position
11
Q
if the brake pedal pressure is lost, what would this indicate?
`
A
a faulty washer
12
Q
if you find that the rear wheels only are binding
what would be the cause?
A
the hand brake is left on
13
Q
what is the prime function of the gear box?
A
to maintain engine revolutions
14
Q
where is the condenser usually located?
A
inside the distributor
15
Q
what is the use of the rotor brush?
A
to deliver current to the spark plugs
16
Q
what is the use of the generator?
A
to provide an electrical charge.
17
Q
if you were driving along at 40 MPH and a battery wire became disconnected,
- would the engine stop running ?
- would the dash board light appear?
- would the engine misfire immediately?
- would the engine lose compression?
A
the dashboard light would appear.
18
Q
where are brakes show adjustments usually located?
A
on the backing plate
19
Q
in which of the following is a pair of plyers used?
- to tighten all nuts
- to tighten only nuts of brass or bronze
- to remove valves
- to remove split pins
A
to remove split pins
20
Q
what are the tools commonly used for adjusting thee distributor points?
A
a screw driver
a feeler gauge
21
Q
what drives a mechanical fuel pump?
A
the camshaft
22
Q
what closes the valves of a 4 stroke single cylinder petrol engine?
A
springs
23
Q
what is used to indicate the oil pump pressure?
A
- a gauge on the dashboard
2. a green light on the dashboard
24
Q
what creates momentum in a 4 stroke petrol engine?
A
the flywheel
25
which is correct?
1. camshaft drives the crankshaft
2. the crankshaft drives the piston
3. the piston operates the valves
4. the crankshaft drives the camshaft
the crankshaft drives the camshaft
26
which of the following could be fitted on a diesel engine?
1. a carburetter
2. high tension coil
3. de-compressor valve
4. a distributor
a de-compressor valve
27
what would you suspect if you noticed thick black smoke coming from the exhaust of your engine?
the carburetter requires adjustment
28
what can cause overheating?
1. poor water circulation
2. binding brakes
3. broken fan bel
4. clogged radiator
29
what would the effect be if the tailpipe became blocked?
there would be a loss of power
30
what precautions should be taken to fill a radiator while it is hot?
1. fill with hot water
| 2. fill with cool water while engine idles
31
what is the most effective way to clean a carburetter???
using a solvent
32
at which point is a spark timed to ignite the mixture of petrol and air?
at the top of the stroke
33
how is power obtained in a 4 stroke petrol engine?
by expansion caused by combustion
34
how is the bleeding of the brake system accomplished?
by expelling air from the system
35
what causes the necessity to keep topping up the master cylinder?
a leak in the brake line or tube
36
if you are driving a diesel truck up a hill and the vehicle stalls in low gear, what should you do?
select reverse gear
37
how many valves are there in a single cylinder engine?
2 valves
38
if you are driving steadily along and your vehicle stops suddenly,
what could be a possible cause?
a disconnected coil wire
39
if there is a leak in the crank case of a 2 stroke engine,
| what effect would this have on the engine?
the engine would be difficult to start
40
if an air lock developed in the fuel system of a diesel engine,
what would be the result?
the engine would shut down
41
why should valves be properly seated?
to ensure good compression
42
why is it unsafe to fill a radiator while the engine is very hot?
1. the water may boil and block back in your face.
| 2. the sudden change in temperature may crack the cylinder head
43
what is an indication of a dirty air cleaner?
loss of power
44
what is the main cause of damage to a manual gear box?
changing gear without using the clutch
45
what is the use of the voltage regulator?
to regulate the charge rate of the generator or alternator
46
if current is going to the distributor points but not the spark plugs,
what could be the fault?
a defective rotor arm
47
is the generator output
1. always constant?
2. variable according to battery condition?
3. of a lower voltage than the battery ?
4. higher than the battery voltage?
variable according to battery condition
48
if a fan belt is adjusted too tightly, what could this cause?
the generator bearing to be worn excessively
49
in what way can a simple test for compression be obtained?
by removing the plugs one at a time and stopping the opening with a finger while the engine is slowly revolving
50
what is the use of the a lug spanner?
to remove lug nuts or bolts
51
where is the clutch pedal located?
to the left of the brake pedal
52
what is the use of a screw driver?
to drive a screw
53
if there is evidence of water in the carburetor,
| what effect will this have on the engine?
it would cause the engine to splutter
54
what would indicate the need for new brake linings?
a drop in the height of the brake pedal
55
why is the hand brake primarily fitted to a car?
to form one of the two braking systems required by law
56
what is usually meant by servicing the gear box?
checking the oil level
57
how many wires are attached to the distributor of a 4 cylinder engine?
6 wires
research for a 1 cylinder engine
58
what is the main purpose of the condenser?
to prevent burning of the points
59
how do you know when the generator is charging properly?
when the red indicator light goes off
60
what may cause the generator to stop charging
1. a broken fan belt
| 2. worn down brushes
61
what would a choke in the petrol line indicate?
a dirty petrol tank
62
what is the use of the clutch?
1. to engage the engine to the gear box
| 2. to disengage the engine from the gear box
63
which of the following are strokes of the engine?
1. combustion
2. power
3. injection
4. suction
combustion
| power
64
what is the primary purpose of the valves in an engine?
to allow mixture to enter and leave the combustion chamber
65
if the green light on the dash board appears when you are driving at 30 MPH.
what could be the caused?
poor oil circulation in the engine
66
if you observe oil continuously appearing in the radiator,
| what would you suspect?
a leaking cylinder head gasket
67
if your tail pipe is blocked with earth, which of the following effects would this have on the engine?
1. misfiring
2. overheating
3. failing to start
4. back firing
failing to start
68
what could cause blue smoke to come from a tail pipe?
over flooding
69
what does spitting back through the intake suggest?
intake valves not properly seated
70
if bubbling in radiator is seen when the cap is removed, what would this suggest?
1. ineffective water pump
2. clogged radiator
3. a clogged water hose`
71
if the carburetor has a leaking base gasket,
| what would this cause?
the engine to idle too fast
72
if the engine will not run smoothly at slow speed, what could be the cause?
1. valves not properly seated
2. carburetor needs adjusting
3. incorrect tappet adjustments
73
what makes it necessary to bleed brakes?
replacement of old brake cylinder washers
74
if you depress the hydraulic pedal 4 times in quick succession and it hits the floor board each time,
what would you suspect?
that the brakes require bleeding
75
if you attempt to select a lower gear while driving down hill and you miss,
what is the safest thing to do?
try to select a higher gear
76
if you have just driven through deep water and your engine begins to misfire
what would you suspect?
shorting out of the plugs and coil
77
if after driving for some time the red trouble light appears on the dash board, what should you do?
look for a loose or broken fan belt or
| check if the generator wire is disconnected
78
if you are driving along and a rumbling noise develops in a front wheel,
what would you suspect?
a defective wheel bearing
79
what would you suspect if water is coming from the tail pipe?
1. crack cylinder block
| 2. damage cylinder head gasket
80
if the vehicle swings to one side when the brake pedal is depressed
what could be the cause?
wet brake lining
81
if there is a spark from the coil but not from the spark plugs,
what would this indicate?
a bad rotor brush
82
what can cause your engine to misfire?
faulty spark plugs
83
what safety precautions should be taken when jacking up a vehicle?
1. scotch the wheels
| 2. remove the occupants of the vehicle
84
when is a tyre defective?
when it is worn to or
| beyond the breaker strip
85
what opens the valves on the compression stroke of a 4 stroke single cylinder petrol engine?
the rocker arms
86
what can be used to alter the mixture or ratio of petrol to air?
the air screw
87
how is effective lubrication maintained in a 4 stroke engine?
by the oil pump pressure
88
how many wires are attached to the distributor cap of a 4 cylinder engine?
5 wires
89
when black smoke is being emitted from a tail pipe
| what does this indicate?
the mixture is too rich
90
what could be the cause of fumes coming into your car ?|
poor engine condition
91
give one reason for a diesel engine failing to start
decompressor valve open
92
if there is evidence of water in your crank case, how would the oil appear to you ?
thick and frothy
93
if an engine does not run smoothly at high speed, what could be the cause?
1. valve springs weak
| 2. faulty ignition
94
how is effective braking in a hydraulic system obtained?
by maintaining fluid level in the reservoir
95
if the vehicle swings to the right when the brakes is applied
what could be the fault?
the left brake lining is wet
96
give one indication of a faulty gear box
abnormal noise coming from the gear box
97
what is the use of the ignition coil?
to provide high tension voltage
98
what is the generator usually driven by ?
a belt
99
what happens when the generator stops charging?
the ignition warning light burns red
100
how is a bad spark plug located?
by shorting out each plug one at a time
101
what is the main difference between a flat screw driver and a phillips?
the design at the working end
102
what is the use of an adjustable spanner?
to do the general work of a spanner
103
does the water pump, pump water from the radiator or from the water jackets?
from the water jackets
104
which is the smallest of the spanner sizes listed?
choices: 11/16, 3/4, 13/16 and 3/8
choices : 3/4, 1/2, 9/16 and 7/16
1. 3/8
| 2. 7/16
105
how are the valves positioned in a 4 stroke single cylinder engine on the compression stroke?
both valves are closed
