What device regulates the mixture of air and fuel in an engine?

The carburetor is the device responsible for mixing air and fuel in an engine. This crucial component operates by using the principle of atmospheric pressure to draw fuel into the airstream, where it is then atomized and mixed with air. The resulting mixture is then delivered to the engine's combustion chambers, where it is ignited to produce power.

The carburetor's functionality relies on its venturi tube design, which creates a pressure drop that draws fuel from the fuel bowl into the air stream. Adjustments to the throttle position can also affect the amount of air and fuel mixture, ensuring optimal performance during different operating conditions.

While the throttle body does control airflow and can influence the amount of mixture entering the engine, it does not itself mix fuel with air, distinguishing its function from that of the carburetor. A fuel injector delivers fuel directly into the combustion chamber or intake manifold but does not mix it with air on its own. An air filter's role is to clean the incoming air before it enters the carburetor or intake, preventing contaminants from entering the engine, thus it does not interact with the air-fuel mixing process.