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If the detergent type lubricating oil being used in a diesel engine is black, the oil （）
A . must be centrifuged
B . must by filtered
C . must be changed
D . is holding finely dispersed carbon in suspensio
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If the speed of a turbocharged diesel engine is maintained constant the turbocharger speed will （）
A . decrease until the engine speed increases
B . increase as the load increases
C . decrease as the load
D . increases remain unchanged
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If the diesel engine fuel injection timing is changed to delay the start of injection until the pistons are at top dead center, the engine will（）
A . backfire through the air intakes
B . develop less power under load
C . have high firing pressures
D . lift its cylinder relief valve
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Which of the following conditions is realized by the turbo-charging of a previously naturally aspirated diesel engine?（）
A . Ignition lag increases
B . Lube oil system pressure increases
C . Brake specific fuel consumption increased
D . Mechanical efficiency increaded
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If a diesel engine fails to start，one of the likely causes is （）
A . low compression temperature
B . low ambient air pressure
C . high lube oil pump pressure
D . high fuel oil booster pump pressure
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If a diesel engines exhaust temperature is abnormally high, the cause could be（）
A . too light of a load
B . injection timing is too early
C . overloading of the engine
D . too low of a compression ratio
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If water is found in the crankcase of a diesel engine, the cause may be due to（）
A . a cracked cylinder head
B . a leaky cylinder head gasket
C . a cracked cylinder liner
D . any of the above
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On a diesel engine equipped with an isochronous governor, if the “speed droop” control is reduced to the “zero” setting, the engine （）
A . speed will drop drastically with any increase in load
B . will stop due to zero fuel supply
C . will stall upon application of load
D . speed will remain fairly constant despite load change
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Which of the following problems may occur if the opening pressure of a fuel injection nozzle is greater than specified by the engine manufacturer?（）
A . The amount of fuel injected will be increased
B . The start of injection will be retarded
C . The nozzle will permit fuel to dribble
D . The spray pattern will be distorted
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If an air compressor is used to supply compressed air to outlets throughout the engine room and on deck of a vessel, the system is known as the （）.
A、combustion control air system
B、supply air system
C、ships service air system
D、low pressure deck air system
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If a single cylinder relief valve on a diesel engine lists frequently while the engine is running, the cause may be an （）
A . excessively late injection timing for each cylinder
B . incorrectly adjusted intake valve timing
C . incorrectly adjusted fuel injector
D . incorrectly adjusted intake valve clearance
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If a diesel engine runs roughly, which of the systems listed is most likely to be at fault?（）
A . Fuel
B . Lubricating
C . Cooling
D . Ignitio
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If a four-stroke/cycle diesel engine is running at 1550 RPM, the speed of the camshaft will be（）.
A . 525 RPM
B . 775 RPM
C . 1550 RPM
D . 1800 RPM
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（） can be found on most medium to large merchant vessels even if the main engine is either a steam turbine or 2-stroke crosshead engine.
A . The medium speed 4-stroke trunk piston engine
B . The low speed 2-stroke crosshead engine
C . The medium speed 2-stroke crosshead engine
D . The low speed 4-stroke trunk piston engine
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The power output of a turbocharged diesel engine will drop if the cooling water flow through the after-cooler is interrupted because the （）.
A . turbocharger stalls
B . exhaust pressure increases
C . air charge density decreases
D . scavenge effect increase
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If a diesel engine is smoking excessively under load, the cause could be （）
A . low exhaust back pressure
B . early fuel injection in one of the cylinders
C . compression pressure in one of the cylinders
D . plugged injector hole
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If an auxiliary diesel engine temperature is higher than normal ,but the thermostat is determined not to be defective you would suspect a /an （）
A . cavitation erosion in the water jackets
B . excess corrosion inhibitor in the coolant
C . dirty jacket water cooler
D . defective turbocharger
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Charging-air pressure increases if there is incorrect combustion and drop in the （） of the diesel engine.
A . machine efficiency
B . machinery efficiency
C . mechanical efficiency
D . mechanics efficiency
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During the running of the diesel engine, if the supply of cooling water is interrupted or the temperature of cooling water out of the cylinder is too high, the duty engineer should （）
A . notify the duty officer, reduce the engine speed, take some measures to remove failures
B . notify the duty officer and stop the engine immediately, find the cause and remove failures
C . notify the C/E
D . notify the captai
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If the coolant temperature of a closed cooling water system for a diesel engine gradually increases, the trouble usually is （）
A . a broken shaft on the freshwater pump
B . an excessive accumulation of scale exchanger
C . an incorrect thermostatic element operating range
D . lube oil in the cooling water
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If you suspect a diesel engine is misfiring due to air leakage into the fuel system, you should begin looking for the leak at the （）
A . fuel line connections to cylinder injection valves
B . gasket surfaces of the fuel oil filters
C . discharge fitting of the fuel injector pumps
D . suction side of the fuel oil tra
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Which of the following conditions will develop if the flow of ‘raw’ cooling water to diesel engine is obstructed?（）
A . Air will enter the cooling system
B . Carbon will plug the water cooled exhaust manifolds
C . The jacket water temperature will rise
D . The lube oil viscosity will increase
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If a diesel engine is difficult to start and operates with the engine temperatures lower than normal, you should suspect that the （）.
A . compression pressures are below normal
B . lube oil is diluted with fuel oil
C . cranking speed is too low
D . exhaust system is partially restricted
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If the scavenge fire is of a more major nature, if there is a risk of the fire extending or if the scavenge trunk is adjacent to the crankcase with risk of a hot spot developing it sometimes becomes necessary to （）the engine.
A . stop
B . start
C . speed up
D . slow dow
