2008-2010 Kawasaki KFX450R Factory Service Manual, Page 336Get this manual
12-24 BRAKES Brake Discs
Disc Wear
thickness Measure thethe mostof each disc at the point [A] where it has worn Replace the disc if it has worn past the service limitDisc Thickness Standard: 3.3 3.7 mm (0.13 0.14 in Service Limit: mm (0.12 in