What is the control principle of idling screw of motorcycle carburetor?

The idling screw of motorcycle generally controls the opening of throttle, and then controls the combustible mixture to enter the engine. When the opening is larger, more combustible mixture enters, and the engine speed is higher, and the corresponding speed is faster and the output power is higher. The idle screw ensures that a certain amount of mixed gas is provided to the engine and that the engine will not stall at the lowest stable speed.