MST Marine Fuel Systems Flashcards
6 cards from real MST practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 6 MST Marine Fuel Systems flashcards as text
What is the proper way to dispose of water-contaminated fuel removed from a marine tank?
Answer: Take it to a certified hazardous waste facility or marina fuel recycler
Contaminated fuel is hazardous waste and must be disposed of at an approved facility — dumping it overboard or on land is a federal violation.
A fuel-injected outboard has low fuel pressure at the rail. After replacing the fuel filter, pressure is still low. What is the next component to inspect?
Answer: The electric fuel pump
If a new filter does not resolve low rail pressure, the electric fuel pump is likely weak or failing and should be tested for volume and pressure output.
Which federal regulation requires marine fuel tanks to be certified for use in boats?
Answer: 33 CFR Part 183 (Fuel Systems)
33 CFR Part 183 establishes Coast Guard standards for fuel systems on recreational boats, including tank certification requirements.
What symptom would a cracked VST (vapor separator tank) O-ring on a four-stroke EFI outboard most likely cause?
Answer: Fuel leak at the VST and possible lean run condition
A cracked VST O-ring allows air to enter the high-pressure fuel circuit and fuel to leak externally, causing lean operation and a visible fuel leak.
Ethanol in marine fuel is known to degrade what common fuel system component?
Answer: Rubber fuel lines and carburetor diaphragms
Ethanol swells and deteriorates older rubber fuel lines, gaskets, and carburetor diaphragms not designed for alcohol-blended fuels.
What is the maximum EPA-allowable ethanol content in marine gasoline sold at the pump?
Answer: 10% (E10)
The EPA limits marine pump fuel to E10 (10% ethanol) because higher concentrations can damage marine engines and fuel system components not designed for them.