2008 Polaris ATV Predator 50, Sportsman Outlaw 90 Service Manual, Page 72Get this manual
ENGINETRANSMISSION 6Install cam chain guidePull cam chain tight so blade will slide into notch in crankcase3Install cam chain sprocket to chain with dot on sprocket at the topSprocket must be timed before cylinder head is installed
Cylinder HeadCamshaft Installation
NOTE: Clean gasket surfaces on cylinder head and cylinder to remove all traces of old gasket material1Install two dowel pin(s) and new cylinder head gasketSlide the head onto studs and guide the sprocket with chain through the cylinder head chain towerInstall cam chain sprocket onto camshaftBe sure dot (A) on sprocket is aligned with mark (B) on cylinder headTurn camshaft to align holes and install sprocket boltsTorque bolts to specificationRotate engine to Top Dead Center.See "Finding Top Dead Center (TDC)" on page 3.13