What function does the inlet needle serve in a carburetor?

The inlet needle in a carburetor has the crucial function of allowing fuel to enter the float bowl as it is consumed by the engine. When the engine runs, fuel is drawn from the float bowl to mix with air and create the combustible mixture necessary for combustion. As fuel is consumed, the level in the float bowl decreases. The inlet needle, which is typically held closed by a float mechanism, opens to let more fuel in from the fuel line to replenish the float bowl when needed.

This system ensures that there is always an adequate supply of fuel for proper engine operation. If the needle did not operate correctly, it could lead to either flooding (if it doesn’t close) or starvation of fuel (if it doesn’t open), both of which would adversely affect engine performance. Thus, option B accurately describes the essential role of the inlet needle in maintaining a steady supply of fuel in the carburetor.