Carburetor operation is central to how many traditional gasoline engines produce power. This mechanical device meters fuel and mixes it with incoming air, creating a combustible mixture that supports efficient combustion inside the engine.
Although modern vehicles often use electronic fuel injection, carburetors remain common in classic cars, motorcycles, small engines, and specialized equipment. Understanding their operation clarifies how fuel delivery affects performance, economy, and engine reliability.
A carburetor meters fuel and mixes it with incoming air before the mixture enters an engine’s cylinders. This process relies on pressure differences created as air flows through the narrow venturi passage.
As air accelerates through the venturi, its pressure decreases. Atmospheric pressure then pushes fuel from the float bowl through calibrated jets into the airstream, where it breaks into fine droplets and mixes with air.
The throttle plate controls engine speed by regulating how much air-fuel mixture reaches the intake manifold. Opening the plate increases airflow and fuel delivery, allowing the engine to produce more power.
A float and needle valve maintain fuel at a consistent level inside the bowl. Choke mechanisms enrich the mixture during cold starts, while idle circuits supply fuel when the throttle is nearly closed.