2001 Polaris Sportsman 400-500 DUSE and H.O. Service Manual, Page 132Get this manual
ONE WAY VALVE INSTALLATION
Install the one way valve plunger, spring, and plug using new sealing washer
One Way Valve Plug Torque: 16 ftlbs(2.2 kg-m)
CAM CHAIN DRIVE SPROCKET INSTALLATION
1Install the Woodruff key, drive sprocket, and slotted nutTighten the nut to the specified torqueB A