2002 Yamaha YFM660 Grizzly factory service and repair manual, Page 162Get this manual
CAMSHAFT AND CYLINDER HEAD
CHECKING THE CAMSHAFT 1.Check: Cam lobes Pittingscratchesblue discoloration Replace2.Measure: Cam lobes length and bOut of specification ReplaceCamshaft lobe limit: Intake: 35.59 mm (1.4012 in) 29.96 mm (1.1795 in) Exhaust: 36.40 mm (1.4331 in) 30.01 mm (1.1815 in)