2001 Yamaha YFM660 Raptor Factory Service Manual, Page 167Get this manual
FRONT ARMS AND FRONT SHOCK ABSORBERS
REMOVING THE FRONT ARM 1.Check: Front arm free play
Checking steps: Check the front arm side play by moving it from side to sideIf side play is noticeable, check the bushingsCheck the front arm vertical movement by moving it up and downIf the vertical movement is tight or rough, or if there is binding, check the bushings