2008 Polaris ATV Sportsman 300 400 H.O. Service Manual, Page 85Get this manual
ENGINE (300) 7Install the flywheel key and flywheel
Piston Installation CAUTION
Do not re-use circlipsCirclips become deformed during the removal processDo not compress the new clip more than necessary to prevent loss of radial tensionSevere engine damage may result if circlips are re-used or deformed during installation12Install new circlip on one side of the piston with the end gap facing up or downApply clean engine oil to the piston rings, ring lands, piston pin bore, piston pin, and piston skirtLubricate the connecting rod (both ends) and crankshaft main bearing area
Flywheel Nut: 67-81 ftlbs(90-110 Nm) Recoil Drive Hub: 12-14 ftlbs(17-19 Nm)