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Protecting the engine after carburetor removal

Aviation Mechanic Powerplant (AMP) practice question 14 of 20 on Engine Fuel and Fuel Metering Systems. ACS element AM.III.I.R3 · difficulty: standard. Want to answer it in a timed quiz? Use the Aviation Mechanic Powerplant (AMP) practice mode.

Question bank updated 2026-09-22

QUESTIONA carburetor has just been lifted off an engine. What should the mechanic do immediately?

  1. AReconnect the throttle and mixture linkage
  2. BSafety wire the throttle valve wide open
  3. CInstall a cover on the mounting flange
Show the answer and explanation

Correct answer: C. Install a cover on the mounting flange

  • A — incorrect Those linkages were disconnected as part of removal and are reconnected only after the replacement unit is bolted on and checked for freedom of movement.
  • B — incorrect The throttle valve is lockwired in the closed position, both during removal and again as soon as the carburetor is placed back on the engine.
  • C — correct A protective cover goes on the carburetor mounting flange immediately, to prevent small parts or foreign material from falling into the engine.

BACKGROUND

When removing a downdraft carburetor, extreme care is needed to ensure that nothing is dropped into the engine. As soon as the carburetor is removed, a protective cover is installed on the carburetor mounting flange of the engine to prevent small parts or foreign material from falling in. On installation, the protective cover is taken off, the mounting flange gasket is positioned so that any bleed hole in the gasket aligns with the passage in the flange, and the induction passages are inspected for foreign material before the carburetor is placed. As soon as the carburetor is in position, the throttle valves are closed and lockwired until the rest of the installation is complete, and the carburetor deck screen is placed where feasible to further exclude foreign objects.

STUDY TIP

Think of every open engine opening as an invitation to foreign object damage and cover it at once. The covering, lockwiring, and deck screen steps all serve the same purpose.

KEY POINTS

  • Install a protective cover on the mounting flange as soon as the carburetor comes off.
  • Inspect induction passages for foreign material before installing a carburetor.
  • Lockwire the throttle valves closed once the unit is in position and fit the deck screen where feasible.

SOURCES

  • amp-powerplant/ch02.txt "Carburetor Removal"
  • amp-powerplant/ch02.txt "Installation of Carburetor"
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SkyDrill is not affiliated with the FAA. This is an original practice item based on FAA-H-8083-32B Aviation Maintenance Technician Handbook – Powerplant, and 14 CFR part 43. Regulations and handbooks are revised; confirm details against the current edition.