2008-2010 Kawasaki KFX450R Factory Service Manual, Page 306Get this manual
11-10 FINAL DRIVE Sprockets
Sprocket Wear Inspection
Visually inspect the front and rear sprocket teeth for wear and damageIf they are worn as illustrated or damaged, replace the sprocket[A] Worn Tooth (Engine Sprocket) [B] Worn Tooth (Rear Sprocket) [C] Direction of Rotation