2012 Sportsman 400/500 and EFI Tractor Service Manual 9923412, Page 129Get this manual
CARBURATION AND FUEL SYSTEM Carburetor Assembly
Inspect the diaphragm (A) for holes, deterioration, or damageMake sure the diaphragm is pliable but not swollenThe diaphragm should fit properly in the carburetor bodyReplace diaphragm assembly if diaphragm is damaged3Install the pilot mixture screw, spring, washer, and ring as an assemblyLubricate the ORing with oil or light grease before installationCAUTION: Do not damage the Oring during installationTurn the screw in until it lightly contacts the seatBack out the specified number of turnsNOTE: The final pilot (idle) mixture must be adjusted with the engine runningRefer to cHAPTER 2Pilot Screw Base Setting (Set at Factory) Factory Specification: Turns Out