Which of the following is NOT a function of the carburetor venturi?

The function of the carburetor venturi primarily revolves around its ability to create a low-pressure area, which is essential for drawing fuel into the air stream. As air flows through the narrowed section of the venturi, the velocity of the air increases, leading to a decrease in pressure according to Bernoulli's principle. This low-pressure area is crucial for aspirating fuel from the float chamber into the venturi where it mixes with the incoming air, forming the air-fuel mixture necessary for combustion.

While the venturi contributes to regulating the air-fuel mixture by facilitating the suction of fuel, it does not directly manage the idle system. The idle system's regulation happens through other components in the carburetor, like the idle jets and adjustment screws, which fine-tune fuel delivery at low throttle positions. Therefore, the statement regarding regulation of the idle system is not a function of the venturi itself, making it the correct choice for what is NOT a function of the carburetor venturi.