ABYC Diesel Certification Exam 2026
Questions and Answers
minimum spacing between hull vent openings and fuel fill or vent fititngs should
be - Correct answer-15 inches
thermal efficiency of a diesel engine is such that typical heat converted to useful
power is approximately what percent of total heat - Correct answer-36%
What is the primary difference between the gasoline-fueled and Jen four stroke
cycle and the diesel four-stroke cycle - Correct answer-The intake stroke only
brings air into the cylinder
Temperature controlled engine room exhaust blowers in a diesel powered boat are
primarily used to - Correct answer-Lower engine room temperatures
With some diesel engines it is necessary to use what when cold starting - Correct
answer-Heat
When setting up a piping system for exhaust gases the number of sharp bins should
be kept to a minimum to - Correct answer-Prevent excessive exhaust back-pressure
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, Who does not have requirements that apply to exhaust components and hose types
- Correct answer-U.s. coast guard
What is the most likely exhaust related cause for excessive engine operating
temperature - Correct answer-Exhaust elbows that are old and clogged
an engine equipped with an exhaust mixing elbow is installed below the waterline
what device must be installed in the raw water discharge hose ahead of the mixing
elbow - Correct answer-Siphon break
Upon inspection of the wet exhaust system the technician notices that the exhaust
hose is burned near the elbow tech a says that replacing the hose will correct the
problem. Tech b says that the problem is most likely with the cooling system which
tech is correct? - Correct answer-Tech b
If you do not refill the raw water system with a winterizing solution for long-term
storage after draining the sea water the system is prone to - Correct answer-
Oxidization
Replacement of a failed sea water pump impeller should normally include -
Correct answer-Checking all downstream components for impeller pieces
During a sea trial for a complaint of high-speed overheating the technician finds
that the cooling hoses are swollen and very firm when squeezed and the exhaust
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Questions and Answers
minimum spacing between hull vent openings and fuel fill or vent fititngs should
be - Correct answer-15 inches
thermal efficiency of a diesel engine is such that typical heat converted to useful
power is approximately what percent of total heat - Correct answer-36%
What is the primary difference between the gasoline-fueled and Jen four stroke
cycle and the diesel four-stroke cycle - Correct answer-The intake stroke only
brings air into the cylinder
Temperature controlled engine room exhaust blowers in a diesel powered boat are
primarily used to - Correct answer-Lower engine room temperatures
With some diesel engines it is necessary to use what when cold starting - Correct
answer-Heat
When setting up a piping system for exhaust gases the number of sharp bins should
be kept to a minimum to - Correct answer-Prevent excessive exhaust back-pressure
©COPYRIGHT 2025, ALL RIGHTS RESERVED 1
, Who does not have requirements that apply to exhaust components and hose types
- Correct answer-U.s. coast guard
What is the most likely exhaust related cause for excessive engine operating
temperature - Correct answer-Exhaust elbows that are old and clogged
an engine equipped with an exhaust mixing elbow is installed below the waterline
what device must be installed in the raw water discharge hose ahead of the mixing
elbow - Correct answer-Siphon break
Upon inspection of the wet exhaust system the technician notices that the exhaust
hose is burned near the elbow tech a says that replacing the hose will correct the
problem. Tech b says that the problem is most likely with the cooling system which
tech is correct? - Correct answer-Tech b
If you do not refill the raw water system with a winterizing solution for long-term
storage after draining the sea water the system is prone to - Correct answer-
Oxidization
Replacement of a failed sea water pump impeller should normally include -
Correct answer-Checking all downstream components for impeller pieces
During a sea trial for a complaint of high-speed overheating the technician finds
that the cooling hoses are swollen and very firm when squeezed and the exhaust
©COPYRIGHT 2025, ALL RIGHTS RESERVED 2
