2008 Polaris ATV Sportsman 300 400 H.O. Service Manual, Page 87Get this manual
ENGINE (300) 5Lubricate the washers and the threads of the cylinder head bolts and install the bolts with washers
Camshaft InstallationTiming CAUTION
Serious engine damage will result if the camshaft is not properly timed to the crankshaftIMPORTANT CAMSHAFT TIMING NOTE: In order to time the camshaft to the crankshaft, the piston must be precisely located at Top Dead Center (TDC)If flywheel key and flywheel are not installed, install them at this timeThe recoil housing must also be temporarily installed to use the timing inspection hole1Rotate the crankshaft until the "T" (Top Dead Center) timing mark on the flywheel is aligned with the mark in the timing inspection window of the recoil housingBe sure to use the correct mark when installing the camDo not use any advance timing marksTorque the cylinder head following the procedure and pattern belowCylinder HeadCylinder Base 2