Which component is primarily responsible for controlling fuel flow in a carburetor?

The float valve is the component primarily responsible for controlling fuel flow in a carburetor. It functions as a gate that regulates the amount of fuel entering the carburetor from the fuel tank. As the fuel level in the float chamber rises, the float itself also rises, eventually pressing against the float valve to close it. This mechanism prevents overfilling and maintains a consistent fuel level in the float chamber, which is crucial for ensuring that the carburetor operates efficiently. A stable fuel level allows for proper atomization and mixing of air and fuel, leading to optimal performance of the engine.

While the throttle plate does regulate the amount of airflow into the engine and thereby affects fuel delivery based on the demand for power, it does not directly control the fuel intake as the float valve does. The main jet is responsible for metering the fuel that mixes with air in the carburetor; however, it relies on the fuel being available in the float bowl, which is dependent on the float valve. The power valve enriches the air-fuel mixture under certain conditions but is also not the primary control for overall fuel flow as influenced by the float valve. Thus, the float valve is crucial for establishing the foundational fuel flow that supports the entire operation of