2008 Arctic Cat ThunderCat ATV Service Manual, Page 29Get this manual
Problem: Engine lacks power Condition 12345678910111213Valve 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 Fuel injector obstructed Air cleaner element obstructed Oil (in the engine) overfilledcontaminated Intake manifold leaking air Cam chain worn
12345678910111213Adjust clearance Replace springs Re-time valve gear Replaceservice ringscylinder Repair seats Cleanreplace plug Replace armsshafts Adjust gapreplace plug Replace injector Clean element Drain excess oilchange oil Tightenreplace manifold Replace cam chain