2008 Polaris ATV Sportsman 300 400 H.O. Service Manual, Page 69Get this manual
ENGINE (300) Cam Chain Guide And Tensioner Blade
123The guide can be removed after cylinder head is removed by pulling it upward out of the channel in the crankcaseRemove blade and inspectReplace if worn, cracked, or damagedTensioner blade removal requires recoil, flywheel, and stator plate removalRefer to lower end service procedures to access the bolt securing the tensioner blade to the crankcase By hand: Placing both thumbs at end gap, carefully spread the ring open and lift ring over piston at the opposite sideUse care to not scratch the ring lands45Repeat procedure for second ringThe oil control ring is three piece design consisting of top and bottom steel rail and center expander sectionRemove the top rail first followed by the bottom rail and expander
Cylinder Inspection