Answer for What is an idle and low speed circuit

When a motor vehicle is not in motion or is moving at a slow: speed at that time the throttle remains completely or partially closed. Because of this, the effect of sucking of the suction stroke is limited to throttle itself. Petrol comes through slow running jet, which is built below and the air comes from air horn. There exists a provision for adjusting the petrol which comes through this passage, for idle speed.