D. Air motor starting D. bleed off all hydraulic pressure from the system
Ans: C Ans: D
806 The minimum speed an engine must attain before ignition can occur depends upon __________.
807 A diesel engine fails to start, even though it can be barred over, but not cranked over. The probable cause is _______.
A. the type and size of the engine A. a seized piston
B. the condition of the engine B. an improperly fitted bearing
C. ambient temperature C. a closed or obstructed air starting line valve
D. all of the above D. insufficient compression
Ans: D Ans: C
808 If an auxiliary diesel engine equipped with an electric starting system cranks very slowly after repeated attempts to start, the cause could be a/an ____________.
809 During extremely cold weather, while starting an engine, it turns too slowly and fails to start. This problem is most likely the result of ____________.
A. low lube oil viscosity A. high fuel oil viscosity
B. low compression pressure B. low fuel oil temperature
C. ring gear with broken teeth C. high lube oil viscosity
D. overheated motor winding D. energized glow plugs
Ans: D Ans: C
810 Improper seating of an air starting check valve in an operating diesel engine is indicated by _____________.
811 Vessels having main engines arranged for air starting are to be provided with at least _________.
A. noise coming from the air starting valve A. one automatic drain serving both containers B. an overheated air supply pipe to the cylinder head B. two air starting containers of approximately equal size C. continuous operation of the starting air compressor C. one control air container and one starting air container D. zero air pressure in the air starting system D. one additional means of starting the main engine
Ans: B Ans: B
812 If control air systems are supplied from starting air receivers, the capacity of the receivers should be sufficient _________.
813 Cold weather starting of a diesel engine is more difficult than warm weather starting due to _____________.
A. to provide for intermittent starting procedures A. use of low viscosity oil in cold weather B. for continued operation of these systems after capacity for the
required number of consecutive starts has been used
B. higher compression pressures reached due to smaller clearances existing in the engine during cold weather
C. to provide a nonreversible engine a minimum of twelve consecutive starts
C. increased drag of pistons and bearings due to increased oil viscosity
D. to enable six consecutive starts of a reversible engine D. increased moisture content of inlet air in cold weather
Ans: B Ans: C
814 Starting aids such as glow plugs, are installed on _____. 815 A diesel engine may fail to start due to _____________.
A. large, direct drive diesel engines A. low air charge temperature
B. diesel engines designed to burn residual fuels B. high cranking speed
C. medium-speed, four-stroke/cycle diesel engines C. excessive fuel dilution of lube oil D. small diesel engines utilizing electric starting equipment D. high compression pressure
Ans: D Ans: A
816 An eight cylinder, air started, two-stroke/cycle direct reversing, marine diesel engine can be started from any crankshaft position only if it has ____________.
817 On a diesel engine, using a distributer type air startingsystem, that is not running, which of the following methods may be used to detect leaking air starting valves?
A. at least three cylinders equipped with air start valves A. Open the cylinder test cocks and check for blowing air.
B. a minimum of five cylinders equipped with air start valves B. Check the position of the air start valve cams.
C. each upper cylinder head equipped with reversible air start valves C. Stop the air compressor and check for pressure drop throughout the system.
D. the cylinders on opposite ends equipped with air start valves D. Feel each air supply line to see which is warm from leaking air.
Ans: A Ans: A
818 If a diesel engine starts firing, but is unable to come up to normal speed, either without load or even under a small load, the cause may be ______________.
819 After changing out the fuel filters the diesel engine fails to restart.
The most probable cause for this condition is a/an ____________.
A. insufficient fuel supply A. low compression
B. faulty governor B. air-bound fuel system
C. high exhaust back pressure C. improper spark
D. all of the above may cause this problem D. change in viscosity
Ans: D Ans: B
820 While underway, which of the following would be the FIRST step in reversing a direct reversing large, low-speed, main propulsion, diesel engine?
821 A ship is propelled by a direct reversing large, slow-speed, diesel engine. One step in reversing the direction of propeller rotation for this vessel is by ______________.
A. Manually trip the overspeed device. A. properly inflating the air operated clutch B. Interrupt the fuel flow to the engine. B. reversing the reduction gears
C. Disengage the safety interlock. C. changing the gear ratio
D. Slide the camshaft to the neutral position. D. reversing the servomotor
Ans: B Ans: D
822 When starting a diesel engine at temperatures below 20°C, the frictional resistance to turning will be _____________.
823 The starting air supply for a diesel engine is generally produced by a/an _____________.
A. reduced by increasing lube oil pressure A. exhaust powered turbocharger
B. controlled by reducing the compression ratio B. Roots-type blower air pump
C. proportional to the lube oil viscosity C. centrifugal air compressor
D. eliminated by heating the intake air D. multistage reciprocating air compressor
Ans: C Ans: D
824 Air motors used for starting some auxiliary diesel engines are generally the type known as a/an ____________.
825 Intercoolers installed on starting air compressors, reduce the possibility of ________________.
A. vane motors A. dust entering the high pressure stage
B. plunger motors B. lube oil carbonization
C. gear motors C. discharge pulsations
D. accumulator motors D. interstage vapor lock
Ans: A Ans: B
826 Starting air valves are held firmly on their seats by ____________. 827 Starting systems for large, low-speed, direct reversing, main propulsion diesel engines are usually _____________.
A. cam rollers on the camshaft A. hydraulic starting motor
B. spring force B. electric starting motor
C. air pressure on top of the valve differential piston C. direct air admission D. air pressure on the bottom of the valve differential piston D. vane type air motors
Ans: B Ans: C
828 Diesel engine air start system check valves are opened by _____________.
829 In a hydraulic starting system, oil to the starting motor flows from the _____________.
A. an air start cam A. accumulator
B. cylinder compression pressure B. reservoir
C. starting air pressure C. hand pump
D. valve springs D. electric pump
Ans: C Ans: A
830 When an air started, four-stroke/cycle diesel engine is being cranked, the starting air is admitted to each cylinder during what would normally be the _____________.
831 If a four-stroke/cycle diesel engine is started by injecting air into the cylinders, the pistons receiving the charge of starting air must be _____________.
A. intake stroke A. on the power stroke
B. compression stroke B. on the exhaust stroke
C. power stroke C. at the end of the power stroke
D. exhaust stroke D. at the start of the intake stroke
Ans: C Ans: A
832 An auxiliary diesel engine may fail to start due to _____________. 833 If a diesel engine rotates slowly when cranked, but does not fire, the ___________________.
A. low exhaust back pressure A. fuel control rack had admitted excessive fuel
B. high lube oil temperature B. engine speed does not match the fuel rack setting
C. insufficient cranking speed C. engine has failed to reach its firing speed
D. excessive fuel atomization D. starter pinion and ring gear contact is not correct
Ans: C Ans: C
834 Which of the routine maintenance procedures listed is required for starting air receivers?
835 Which of the following problems can occur if you continually fail to drain off condensate from a starting air receiver?
A. Frequent draining of accumulated moisture. A. Corrosion and eventual failure of the tank.
B. Frequent testing of relief valves. B. Gumming of the tank relief valves.
C. A close watch on temperature to prevent fluctuations in pressure. C. Immediate failure of components downstream of the compressed air system.
D. Frequent cleaning to remove oil and foreign matter. D. Boiling of the water oil mixture as pressure is reduced.
Ans: A Ans: A
836 When attempting to start a main propulsion diesel engine, the engine turns at the proper speed but will not start. You should check the _____________.
837 A four-stroke/cycle, 1000 horsepower diesel engine fails to start at normal cranking speed with normal fuel pressure and ambient temperature. The reason for the failure could be
_______________.
A. starting air pressure A. glazed liners or pistons
B. scavenge air pressure B. high lube oil pressure
C. overspeed trip C. excessive compression ratio
D. banjo oiler line D. worn valve seats and valves
Ans: C Ans: D
838 Which of the listed items should be secured before performing any maintenance on a solenoid operated air start valve?
839 When starting air is admitted, a diesel engine turns over very slowly without firing. The cause may be ______________.
A. Electric power A. an obstruction in an engine cylinder
B. Lube oil standby pump B. water accumulation in some engine cylinders
C. Hydraulic switch C. low starting air pressure
D. Motor drain D. low scavenge air pressure
Ans: A Ans: C
840 A pilot-operated, main air starting valve begins leaking in one cylinder while the engine is operating. This malfunction is indicated by ____________.
841 Hydraulic starters are installed on many lifeboat diesel engines instead of comparable air start systems, because ____________.
A. an increase in the exhaust temperature reading for that cylinder A. hydraulic starters are the least expensive of all starting systems
B. an increase in the starting air manifold pressure B. the system does not require high pressure piping
C. high exhaust pressure C. hydraulic systems turn diesel engines at higher rates of speed than
air starters
D. an overheated air supply line to that cylinder D. the system can be manually recharged
Ans: D Ans: D
842 If a diesel engine fails to start, one of the likely causes is _____________.
843 A diesel engine may fail to start when being cranked, due to _____________.
A. low compression temperature A. high cetane number
B. low ambient air pressure B. insufficient compression
C. high lube oil pump pressure C. low lube oil viscosity
D. high fuel oil booster pump pressure D. high lube oil pressure
Ans: A Ans: B
844 If a hydraulic starting motor turns, but the diesel engine does not, the most likely cause is ____________.
845 A bendix drive starting motor disengages the drive gear from the flywheel by ______________.
A. excessive viscosity in the hydraulic fluid A. spring force
B. a malfunctioning overrunning clutch B. rotating of the starting cam
C. loss of accumulator precharge C. the high rotating speed of the flywheel
D. air in the hydraulic system D. applying accumulator pressure
Ans: B Ans: C
846 A diesel engine electric starting motor is operated under a no-load condition. Continuing to operate the motor unloaded will _______________.
847 If the diesel engine starter-drive mechanism fails to disengage after the engine starts, which of the following situations will occur?
A. disengage the throw out bearing A. The engine will stall.
B. overspeed and cause serious damage B. The starter motor will have reverse current.
C. fail to develop normal speed C. The engine flywheel will be burred.
D. cause the pinion to fail D. the starter motor will overspeed
Ans: B Ans: D
848 During maneuvering operations for a direct reversing large, low-speed, main propulsion diesel engine, which of the following actions is used to stop the shaft from turning prior to reversing the engine rotation?
849 The pilot valves in an air pilot starting system for a two-stroke/cycle, direct-reversing, main propulsion diesel engine are operated by either a ported distributor disc or a/an _____________.
A. Flywheel inertia A. regulator valve
B. Admission of starting air B. quick opening main air valve
C. The way of the vessel C. pilot air start check valve
D. securing of fuel to the cylinders D. individual cam for each pilot valve
Ans: B Ans: D
850 A two-stroke/cycle diesel engine requires less starting air than a four-stroke/cycle diesel engine, of equal displacement, because the two-stroke/cycle diesel engine _____________.
851 Which of the listed types of starting systems is often used on large, low-speed, direct reversing, main propulsion diesel engines?
A. has little or no internal friction A. Electric
B. has a lower effective compression ratio B. Hydraulic
C. operates with scavenge air under a positive pressure C. Air
D. operates without energy absorbing intake and exhaust strokes D. all of the above
Ans: D Ans: C
852 The timing of diesel engine air starting valves is controlled by _____________.
853 Which of the types of motors listed is used in a hydraulic starter?
A. the air start valve timing gears and rods A. Piston
B. a cylinder check valve B. Gear
C. individual cams and valve gear C. Turbine
D. an air manifold poppet valve D. centrifugal
Ans: C Ans: A
854 An accumulator used in a hydraulic starting system is generally located between the _____________.
855 The device used to store a charged pressure for an hydraulic starting system is called the _____________.
A. pump and the compressor A. reservoir
B. storage tank and the pump B. hand pump
C. starting motor and the reserve tank C. accelerator
D. pump and the starting motor D. accumulator
Ans: D Ans: D
856 The pinion of an electric starting motor used with a diesel engine engages the flywheel ring gear by a/an ____________.
857 Auxiliary diesel engine electric starting motors use ____________.
A. automatic follow-up A. alternating current
B. muff coupling and release B. 400 cycle per second motor-generators
C. friction-type clutch C. low amp, high voltage AC
D. bendrix drive or similar mechanism D. direct current
Ans: D Ans: D
858 In a starting motor equipped with a Bendix drive, the pinion moves and meshes with the flywheel ring gear due to __________.
859 A large two-stroke/cycle direct reversing diesel engine is to be reversed. Prior to the admission of starting air you must ____________.
A. the mechanical linkage A. line up the engine for restarting with light diesel oil
B. the threaded sleeve's rotation B. reposition the fuel injection cam
C. centrifugal force C. change the intake and exhaust valve cam positions
D. electromotive force D. place the starting cam in the intermediate position
Ans: B Ans: B
860 In a medium-speed marine propulsion engine equipped with direct air starting valves, the cylinders without air starting valves fire first because the ____________.
861 Two air compressors are provided for the starting air system and should be capable of ______.
A. operation is under higher compression A. charging the starting air containers within one hour B. fuel is admitted only to these cylinders during cranking B. providing the minimum quantity of starting air at all times C. compression is released during starting by opening the exhaust
valve
C. supplying all the air necessary to start both the main engine and an auxiliary at the same time
D. cylinders are not chilled by the expansion of the starting air D. topping of all receivers at the required design pressures
Ans: D Ans: A
862 If cranking a diesel engine is too slow while attempting to start, it will result in _____________.
863 In an operating diesel engine, which of the following conditions is an indication of a leaking air starting valve?
A. insufficient heat of compression A. Noise coming from that air starting valve.
B. fouling of the air intakes B. Continuous operation of the starting air compressor.
C. improper injection timing C. Zero air pressure in the air starting system.
D. high exhaust temperatures D. Overheated starting air pipe to the cylinder head.
Ans: A Ans: D
864 Each receiver in a starting air system which can be isolated from a relief valve _______________.
865 Air receivers installed in starting air systems are to be ________.
A. is to be provided with a suitable fusible plug to relieve the pressure in case of fire
A. cylindrical in shape with service connections located at the top and bottom
B. will incorporate the use of an automatic unloading device B. opened and made available for inspection during biannual inspections
C. will not be approved for classification purposes C. provided with automatic drain traps for the removal of moisture
D. and satisfy classification regulations shall be approved D. so installed as to make the drain connections effective under extreme conditions of trim
Ans: A Ans: D
866 A diesel engine may be hard to start if the _____________. 867 The total starting air capacity required for reversible main engines is to be sufficient for a least __________.
A. air intake is restricted A. six consecutive starts
B. engine is cranked too fast B. eight consecutive starts
C. vibration dampener is faulty C. ten consecutive starts
D. exhaust back pressure is low D. twelve consecutive starts
Ans: A Ans: D
868 What preventative maintenance should be done frequently to diesel engine starting air receivers?
A. Drain the accumulated moisture.
B. Test the relief valves.
C. Watch the temperature to prevent fluctuations in pressure.
D. Clean the interior to remove oil and foreign matter.
Ans: A
869 Heat exchangers are most commonly found in a small auxiliary diesel engine ____________.
870 One advantage of vacuum feed type cylinder lubricators over the liquid sight glass type is ______________.
A. fuel oil system A. there are fewer moving parts
B. governing system B. adjustment is not required
C. air starting system C. better metering accuracy
D. lube oil system D. a lower grade of oil may be used
Ans: D Ans: C
871 Which of the following devices controls the discharge flow rate of an attached, positive displacement, rotary gear, diesel engine, lube oil pump?
872 Mechanical lubricators for diesel engine cylinders are usually small reciprocating pumps which are _____________.
A. A pressure regulating valve A. operated manually once each hour
B. A pressure relief valve B. operated until the engine has started
C. The engine speed C. placed into operation only at maximum load
D. An orifice D. adjustable to meet lubrication requirements
Ans: C Ans: D
873 Which of the following statements is true concerning an oil cooler? 874 Lubrication for the main reduction gears used with diesel engines is usually supplied by _____________.
A. The oil temperature is less than the cooling water temperature. A. oil from the main engine sump
B. The oil pressure is less than the cooling water pressure. B. an independent lube oil system C. The oil pressure is greater than the cooling water pressure. C. the stern bearing head tank D. The oil flow control valve is always installed in the oil input line D. the stern bearing sump tank
Ans: C Ans: B
875 Which of the following devices is normally provided to prevent oil starvation in a diesel engine lubrication system utilizing the "full flow" principle?
876 A large, low-speed, crosshead, main propulsion diesel engine using residual fuel oils must have a cylinder oil having a ____________.
A. Duplex strainer A. low TBN value
B. Three-way valve B. high alkaline reserve
C. Pressure relief bypass line around the filter C. low fclearance point
D. Mechanical straining filter D. high pour point
Ans: C Ans: B
877 Many lube oil filters have pressure gauges installed on both the inlet and outlet in order to indicate the pressure drop across the filter. In normal operation, the pressure drop will _____________.
878 The rate of cylinder lubricating oil metered to each cylinder of a large, low-speed, main propulsion diesel engine is
______________.
A. slowly increase A. the same, whether at sea, or during maneuvering
B. slowly decrease B. adjusted during each hour of operation while at constant RPM
C. remain the same C. higher at sea than while maneuvering
D. have no effect on filter operation D. lower at sea than while maneuvering
Ans: A Ans: C
879 Lube oil cannot be efficiently filtered if its ____________. 880 A dirty lube oil strainer can result in _____________.
A. viscosity is too low A. crankcase dilution
B. temperature is too low B. low lube oil temperature
C. pump discharge pressure is higher than the system's pressure C. excessive oil consumption LUBRICATING SYSTEMS
D. pump capacity is greater than the system's needs D. low bearing oil pressure
Ans: B Ans: D
881 Lube oil filters remove contaminants more efficiently if the oil being filtered is _____________.
882 The pressure differential across a diesel engine lube oil system duplex filter should be checked to _________.
A. under high pressure A. determine the need for filter changing
B. under low pressure B. measure any change in oil viscosity
C. heated to reduce viscosity C. prevent damage to the filter
D. cooled to increase viscosity D. determine the need for batch filtration
Ans: C Ans: A
883 Lube oil in the fresh water cooling system of a diesel engine may
883 Lube oil in the fresh water cooling system of a diesel engine may