ABYC Diesel Certification 2024 Questions And Correct Answers

minimum spacing between hull vent openings and fuel fill or vent fittings should be - ANS 15 inches thermal efficiency of a diesel engine is such that typical heat converted to useful power is approximately what percent of total heat - ANS 36% What is the primary difference between the gasoline-fueled and Jen four stroke cycle and the diesel four-stroke cycle - ANS The intake stroke only brings air into the cylinder Temperature controlled engine room exhaust blowers in a diesel powered boat are primarily used to - ANS Lower engine room temperatures With some diesel engines it is necessary to use what when cold starting - ANS Heat When setting up a piping system for exhaust gasses the number of sharp bins should be kept to a minimum to - ANS Prevent excessive exhaust back-pressure Who does not have requirements that apply to exhaust components and hose types - ANS U.s. coast guard What is the most likely exhaust related cause for excessive engine operating temperature - ANS 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 - ANS Siphon break Upon inspection of the wet exhaust system the technician notices that the exhaust hose is burned near the elbow tech and 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? - ANS 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 - ANS Oxidation Replacement of a failed sea water pump impeller should normally include - ANS 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 hose very hot to the touch this most likely indicates - ANS Exhaust manifold or risers are blocked Technician A says that you must observe USCG regulations when choosing and installing c Cox. Tech b says there is no standard for Seahawks or their installation. What tech is correct - ANS Neither tech is correct during engine operation a technician notices that the water level is low in the sea water strainer this might indicate which of the following - ANS sea water strainer has an air leak and sea water inlet problems The most common cause of low coolant temperature in a closed cooling system is - ANS A faulty thermostat Auxiliary heating devices such as cabin heaters and water heaters may require - ANS Using a restrictor fitting and installing the device lower than the expansion tank The transfer of heat through the fluid in the cooling system is known as - ANS Convection Exhaust gas is leaking into the coolant system may be caused by a defective - ANS Cylinder head gasket Coolant conditioner filters should be replaced - ANS Follow the manufacturer's recommendation Exhaust gas is leaking into the coolant system may be caused by a - ANS Cylinder head gasket What is the maximum cold cranking amps allowed before a battery switches required - ANS 800 CCA Starter ground circuit resistance check should be made by connecting the voltmeter where - ANS Across the ground circuit and measure while cranking For the same length of wire, a 12 gauge wire will safely carry more what than a 16 gauge wire - ANS Amperage When checking a 12-volt DC starter system with the engine cranking the voltmeter should read approximately how many volts - ANS 10 volts When using a conductance battery tester technician finds that the tested battery CCA rating is 65% RV batteries specified rating the battery needs to be - ANS Replaced The purpose of the rubber hub on some propellers is to - ANS Prevent damage to the transmission in the event the propeller strike floating the race When the air is drawn into the propeller from the surface of the water it is called - ANS Ventilation You need to use an alignment tool before installing the outdrive to ensure that the outdrive input shaft and crankshaft coupler are aligned. This prevents - ANS Unnecessary wear to universal joint, unnecessary where to coupler, and vibration Based on a b y c standard the range of clearance between a Cutlass bearing and a shaft that is 1 and 1/2 in in diameter would be - ANS .004 to .009 in When filling the outdrive with lubricant the lubricant should typically be installed through - ANS The bottom drain hole on the gear case