2008 Polaris Sportsman 500 EFI/X2/Touring/500 H.O. Service Manual, Page 103Get this manual
ENGINE Cam Chain Drive Sprocket Installation
1Install the Woodruff key, drive sprocket, and slotted nutTighten the nut to the specified torqueB NOTE: The top rail has locating tab to prevent rotationThe tab must be positioned in the notch on the side of the piston as shown (A)Tighten 3Slotted Nut Torque: 35-51 ftlbs(47-69 Nm) 4Install the bottom rail with the gap at least 30o from the end of the expander on the side opposite the top rail gapSee ILL1)Install the second ring with the "R" mark facing upPosition the end gap toward the rear (intake) side of the pistonInstall the top ring (chrome faced) with the "R" mark facing up and the end gap facing forward (toward the exhaust)(See ILL1)Check to make sure the rings rotate freely in the groove when compressedRing Profile