2003 Polaris Deep Snow Snowmobiles Service Manual, Page 138Get this manual
FUEL SYSTEMCARBURETION The pilot system's main function is to meter fuel at idle and low speed drivingThough its main function is to supply fuel at low speed, it does feed fuel continuously throughout the entire operating rangeFuel for the pilot jet is drawn from the float bowl, mixed with air regulated by the air screw, and delivered to the engine through the pilot outletThe mixture is regulated to some degree by adjusting the air screwWhen the air screw is closed, the fuel mixture is made richer as the amount of air is reducedWhen the air screw is opened, the mixture is made more lean as the amount of air is increased
Pilot Jet
From idling to low speeds, the fuel supply is metered by the pilot jetThere are several air bleed openings in the sides of the pilot jet which reduce the fuel to mistThe number stamped on the jet is an indication of the amount of fuel in cc's which passes through the jet during one minute interval under given set of conditions