ABYC Diesel Exam Practice questions with verified
answers
A customer complains about decreased performance and higher fuel
consumption. What is the proper sequence of tests a technician might consider
for a mechanically fuel-injected engine? Ans✓✓✓-Gather boat history
Visually inspect boat condition and water line
No load RPM
Boost test
Compression Test
a customer complains of white smoke only when the engine is cold. Technician A
says that this could be caused by a faulty pre-heat device. Technician B says that
the white smoke is caused by partially vaporized fuel. Who is right? Ans✓✓✓-
Both technicians are correct
A customer complains the engine idle is rough. Technician A says air in the fuel
system may be the cause. Technician B says the fuel shut-off solenoid is not
operating. Who is correct? Ans✓✓✓-Technician A
A leak in piping connections between the turbocharger and engine intake
manifold could cause the engine to Ans✓✓✓-Emit dark and black exhaust
A ruptured oil cooler core mat result in Ans✓✓✓-water in the oil system
or
oil in the water system
, a technician determines a history of excessive water contaminated fuel. the
operator has been using a variety of fuel sources. the LEAST likely cause is
Ans✓✓✓-the fuel source is contaminated
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? Ans✓✓✓-
damaged flywheel flex-plate
According to ABYC standard H-33, in diesel fuel systems with multiple engines
and/or multiple tanks Ans✓✓✓-fueling valves must be labeled as to function and
position
According to ABYC standards, what is the minimum bend radius of a control
cable? Ans✓✓✓-Manufacturer's recommended minimum
after severely overheating his engine and making the required repairs the
customer complains of excessive coolant usage. your test show that during
normal running the engine does NOT overheat, but coolant is pushing out through
the over flow tube of the expansion tank. what would most likely NOT be the
cause? Ans✓✓✓-raw water pump impeller
an indication of alternator output can be obtained by Ans✓✓✓-comparing
battery voltage with engine running and not running
At high speed the raw water pressure shows heavy fluctuation as indicated on a
pressure gauge. A possible cause would be: Ans✓✓✓-Clogged exhaust riser
Black soot around the engine compartment openings might indicate: Ans✓✓✓-
Insufficient engine room ventilation
answers
A customer complains about decreased performance and higher fuel
consumption. What is the proper sequence of tests a technician might consider
for a mechanically fuel-injected engine? Ans✓✓✓-Gather boat history
Visually inspect boat condition and water line
No load RPM
Boost test
Compression Test
a customer complains of white smoke only when the engine is cold. Technician A
says that this could be caused by a faulty pre-heat device. Technician B says that
the white smoke is caused by partially vaporized fuel. Who is right? Ans✓✓✓-
Both technicians are correct
A customer complains the engine idle is rough. Technician A says air in the fuel
system may be the cause. Technician B says the fuel shut-off solenoid is not
operating. Who is correct? Ans✓✓✓-Technician A
A leak in piping connections between the turbocharger and engine intake
manifold could cause the engine to Ans✓✓✓-Emit dark and black exhaust
A ruptured oil cooler core mat result in Ans✓✓✓-water in the oil system
or
oil in the water system
, a technician determines a history of excessive water contaminated fuel. the
operator has been using a variety of fuel sources. the LEAST likely cause is
Ans✓✓✓-the fuel source is contaminated
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? Ans✓✓✓-
damaged flywheel flex-plate
According to ABYC standard H-33, in diesel fuel systems with multiple engines
and/or multiple tanks Ans✓✓✓-fueling valves must be labeled as to function and
position
According to ABYC standards, what is the minimum bend radius of a control
cable? Ans✓✓✓-Manufacturer's recommended minimum
after severely overheating his engine and making the required repairs the
customer complains of excessive coolant usage. your test show that during
normal running the engine does NOT overheat, but coolant is pushing out through
the over flow tube of the expansion tank. what would most likely NOT be the
cause? Ans✓✓✓-raw water pump impeller
an indication of alternator output can be obtained by Ans✓✓✓-comparing
battery voltage with engine running and not running
At high speed the raw water pressure shows heavy fluctuation as indicated on a
pressure gauge. A possible cause would be: Ans✓✓✓-Clogged exhaust riser
Black soot around the engine compartment openings might indicate: Ans✓✓✓-
Insufficient engine room ventilation
