What mechanical action is performed by the carburetor in a small motor?

The carburetor plays a crucial role in the operation of a small motor by adjusting the air-fuel ratio. This mechanical action involves mixing the right amount of air with the fuel to create a combustible mixture that can efficiently burn in the engine's combustion chamber. The carburetor controls this mixture based on various factors, such as engine speed and load, ensuring that the engine runs smoothly and efficiently. An optimal air-fuel ratio is essential for maximizing power output, fuel efficiency, and reducing harmful emissions.

In contrast, igniting the fuel mixture is the function of the spark plug rather than the carburetor. While generating an electric spark is also the role of the spark plug, filtering exhaust gases is part of the exhaust system, not the carburetor's function. Therefore, the correct association of the carburetor is its ability to finely tune the mixture of air and fuel for optimal engine performance.