2002 Yamaha YFM660 Grizzly factory service and repair manual, Page 294Get this manual
FRONT WHEELS AND BRAKE DISCS
CHECKING THE FRONT BRAKE DISC 1.Check: Brake disc Gallingdamage Replace2.Measure: Brake disc deflection Out of specification Check the wheel runoutIf wheel runout is within the limits, replace the brake discBrake disc maximum deflection: 0.15 mm (0.006 in)