Carburetor Ice | Carb Heat | FlightInsight - FlightInsight A carburetor is used on some aircraft engines as the means of fuel induction into the engine, it can be located on the bottom of some engines. A float type carburetor uses a constricted throat to create a venturi, sucking fuel and air through into the engine intake. A butterfly valve is opened and closed using the throttle control in the cockpit. When the throttle is fully opened, a great deal of fuel and air is sucked in and high power is produced. When the throttle is closed slightly, less fuel and air is brought into the engine and power production is decreased.