2009 Polaris Scrambler 500 4x4 2x4 factory service manual, Page 114Get this manual
FUEL SYSTEMCARBURETION
CARBURETOR INSPECTION
1Inspect jet needle and needle jet for wearLook for discoloration, shiny spots, or an area that looks different than the rest of the needleThe middle to upper portion of the needle contacts the needle jet and is the most likely wear pointIf jet needle shows signs of wear replace both the needle and needle jet to prevent rich conditionTIP: worn needle jet is difficult to spotTo check, slide slightly larger new jet needle into the needle jet and hold it to light sourceLight will be visible between the needle and needle jet if it is worn
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 damaged