2008 Polaris ATV Sportsman 300 400 H.O. Service Manual, Page 74Get this manual
ENGINE (300) Oil Pump InspectionRemoval
NOTE: Mark the oil pump geroters to keep parts mated for assembly12Remove recoil housing, flywheel, flywheel key, and statorUse feeler gauge to check oil pump rotor tip clearance at (A), and pump body clearance at (B)Compare to specificationsReplace the oil pump assembly if any parts are damaged, scored, or measure beyond the service limit
Starting Clutch and Engine Braking Clutch RemovalInspection
NOTE: The transmission must be removed from the engine to access the starting clutch and one-way engine braking clutch1Inspect the starting clutch drum bearing in the housingThe shaft must turn smoothly (by hand) without binding in the clockwise direction, and should not turn by hand in the counter clockwise directionMinimal movement in the shaft is NORMAL with engine removed due to the lack of clutch cover bearing support on the free end of the shaft (approximately 0-.060" (0-1.5mm)Press the shaft out of the housing and replace the bearing if worn or roughDO NOT LIFT ENGINE WITH CLUTCH SHAFT