2008 Polaris ATV Sportsman 300 400 H.O. Service Manual, Page 105Get this manual
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 Oring 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 2
Pilot Mixture Screw Base Setting Factory Specification: Sportsman 3002.5 Turns Out Sportsman 400 H.O- 2.75 Turns Out Float Height Adjustment
1Place the throttle side of the carburetor on level surface to remove weight from float armIn this position, the float tongue will rest slightly outwardReplace parts in proper orderThe spring seat (B) is stepped and must be placed on TOP of "E" Clip (C)Spacer washer (D) must be installed below the EClipRefer to parts manual for more informationBe sure the tab (E) on outer edge of diaphragm is positioned properly in the carburetor body2