2001 Yamaha YFM660 Raptor Factory Service Manual, Page 202Get this manual
CAMSHAFT AND CYLINDER HEAD 2.Install: Camshaft Camshaft sprocket
Installation steps: Turn the crankshaft counterclockwise with wrenchAlign the "I" mark on the rotor with the stationary pointer on the crankcase coverWhen the "I" mark is aligned with the stationary pointer, the piston is at the Top Dead Center (T.D.C
CAUTION:
Do not turn the crankshaft during the camshaft installation
Temporarily