2011 Arctic Cat 450XC Service Manual, Page 24Get this manual
Problem: Engine lacks power Condition 123456789101112Valve clearance incorrect Valve springs weak Valve timing incorrect Piston ring(s)cylinder worn Valve seating poor Spark plug fouled Rocker armsshafts worn Spark plug gap incorrect Air cleaner element obstructed Oil (in the engine) overfilledcontaminated Intake manifold leaking air Cam chain worn
123456789101112Adjust clearance Replace springs Re-time valve gear Replaceservice ringscylinder Replace cylinder headvalves Cleanreplace plug Replace armsshafts Adjust gapreplace plug Clean element Drain excess oilchange oil Tightenreplace manifold Replace cam chain