69. one of the following causes may also contribute to overheating of an engine
A. clogged radiator cores
B. low idle speed setting
C. excessive valve tappet clearance
D. lubricating oil pressure is too high
70. Engine develops less power due to
A. defective ignition timing
B. excessive rich mixture
C. defective lubrication system
D. too tight cylinder head
71. The high fuel consumption of a petrol engine may be due to
A. leakage of fuel from carburetor
B. defects in lubrication system
C. air leaks in intake manifold
D. incorrect idle speed ( too low )
72. Engine does not start because of
A. absence of fuel filters
B. punctured float
C. low viscosity of engine oil
D. less water in radiator