Which carburetor type meters fuel through fixed jets according to the mass airflow and discharges it under positive pressure?

• A. Pressure carburetor
• B. Float-type carburetor
• C. Electronic carburetor
• D. Vacuum carburetor

Answer: (A)

The key idea here is how some carburetors meter fuel: it uses fixed jets to determine the amount of fuel for a given amount of air, and that fuel is discharged into the airstream under positive pressure. In a pressure carburetor, as air flows through the venturi, the airflow creates a pressure differential that drives fuel through fixed jets into the booster section, and that fuel is introduced into the incoming air with positive pressure rather than being drawn in by suction. This keeps fuel delivery proportional to the mass of air the engine is drawing, across throttle positions and altitudes.

This is different from a vacuum-type carburetor, which relies on intake manifold suction to pull fuel into the airstream, and from other types that don’t specifically meter with fixed jets under positive pressure. So the description matches the pressure carburetor.