ABYC DIESEL ENGINE CERTIFICATION EXAM COMPREHENSIVE QUESTIONS AND ANSWERS 100% A+ GRADED EXCELLENCE

ABYC DIESEL ENGINE CERTIFICATION EXAM COMPREHENSIVE QUESTIONS AND ANSWERS 100% A+ GRADED EXCELLENCE Black soot around the engine compartment openings might indicate: - CORRECT ANSWER-Insufficient engine room ventilation if the engine does not achieve full rpm, what test would be the last to be performed? - CORRECT ANSWER-compression check The exhaust blower switch is activated but the sound coming from the blower is not normal. After a period of time, the breaker trips. What is the most likely cause? - CORRECT ANSWER-Blower motor armature bearings are seizing what component is/are installed to provide proper clearance about the outside water line? - CORRECT ANSWER-Exhaust flapper and riser extension Diesel exhaust systems produce small amounts of a dangerous gas, the gas is: - CORRECT ANSWER-Carbon Monoxide While many exhaust silencers can do a good job of reducing noise level, they will be unacceptable if they - CORRECT ANSWER-set up objectionable back pressure What wet exhaust system is best used with engines at or below the water line - CORRECT ANSWER-Water lift Following a recent reposer, the owner complains of overheating at high speed. Technician A says that the thermostats are most likely the problem. Technician B says that the seawater intake system should be checked against the MFG specifications, who is correct? - CORRECT ANSWER-Technician B During operation of the boat the technician notes an oil slick at the exhaust outlet. This most likely indicates - CORRECT ANSWER-There is a leak in the raw water cooler Technician A says the impellers should be routinely replaced. Technician B says that you can extend the life if you reverse the impeller's direction. Who is Correct? - CORRECT ANSWER-Technician A Sacrificial anodes are used for galvanic protection in hear exchangers because they are - CORRECT ANSWER-More anodic than other alloys in the system When re-installing an oil cooler, technician A says that the oil flow should be opposite that of the water flow. Technician B says that the oil and water flow should go in the same direction. Who is correct? - CORRECT ANSWER-Technician A When draining a seawater cooled engine, the technician removes a drain plug and no water comes out. What is the most likely cause? - CORRECT ANSWER-it may be blocked, use a tool to remove the blockage What component is used to transfer heat from engine coolant to seawater in a closed cooling system? - CORRECT ANSWER-heat exchanger What doe MSDA stand for? - CORRECT ANSWER-Material Safety Data Sheets Exhaust gases leaking into the coolant system may be caused by a defective - CORRECT ANSWER-Cylinder-head Gasket Coolant conditioner filters should be replaced: - CORRECT ANSWER-According to manufacturers specification Premature engine drive belt failure may be caused by - CORRECT ANSWER-misalignment of pulleys Which factors must be considered when installing/adjusting the transmission shift cable? - CORRECT ANSWER-second station controls cracks in the jacket kinks or tight bends The owner complains that it takes two hands to operate a single lever control. Technician A says that the cable may be too long and improperly routed. Technician B says that the control head may need cleaning and lubricating. Which technician is correct? - CORRECT ANSWER-Both are correct To adjust a control cable, the technician should: - CORRECT ANSWER-Adjust the terminal eye/cable anchor on the cable According to ABYC standards, what is the minimum bend radius of a control cable? - CORRECT ANSWER-Manufacturer's recommended minimum Modern battery testing techniques would include the use of a - CORRECT ANSWER-DVOM conductance battery testing may require input - CORRECT ANSWER-CCA or MCA` The ground circuit resistance check ( voltage drop) should be made by connecting the voltmeter - CORRECT ANSWER-across the ground circuit and observe the meter while cranking If the electric starter will not crank the engine, the problem may be caused by - CORRECT ANSWER-a run-down battery a defective starter internal engine problems When testing a starter motor circuit, lower than normal amp clamp reading may indicate: - CORRECT ANSWER-a loose / corroded cabling an indication of alternator output can be obtained by - CORRECT ANSWER-comparing battery voltage with engine running and not running a technician is hearing a medium frequency rattle with the engine in neutral located at the flywheel end of the engine. What is a possible cause? - CORRECT ANSWER-damaged flywheel flex-plate compared to gasoline, diesel fuel is more susceptible to - CORRECT ANSWER-microbe contamination According to ABYC standard H-33, in diesel fuel systems with multiple engines and/or multiple tanks - CORRECT ANSWER-fueling valves must be labeled as to function and position When installing new primary filters, the correct micron rating must be observed for the following reasons - CORRECT ANSWER-Micron rating too large will pass debris Micron rating to small could restrict flow A leak in piping connections between the turbocharger and engine intake manifold could cause the engine to - CORRECT ANSWER-Emit dark and black exhaust when changing the primary fuel filter on the a Diesel engine, a technician discovers black stringy material in the filter. This condition is most likely caused by - CORRECT ANSWER-fuel contamination