1985-1995 Polaris ATV and Light Utility Hauler Service Manual, Page 344Get this manual
ENGINESCARBU RETION Pilot System The pilot system's main function is to meter fuel at idle and low speed driving, although it feeds fuel continuously throughout the entire operating rangeFuel for the pilot jet is drawn from the float bowl, mixed with the air regulated by the air screw, and delivered to the engine through the pilot outletThe mixture is regulated to some degree by air screw adjustmentWhen the air screw is closed the amount of air is reduced, causing the fuel mixture to become richerWhen the air screw is opened the amount of air is increased, causing the mixture to become leaner