1997 Yamaha YFM600FWAK ATV Service Manual, Page 286Get this manual
ELECTRIC STARTING SYSTEM
STARTER MOTOR INSPECTION 1.lnspect: Commutator Dirty -t Clean it with #600 grit sandpaper2.Measure: Commutator diameter Out of specification -t Replace the starter motor
Outside diameter: 28 mm (1.10 in) Wear limit: 27 mm (1.06 in 3.Measure: Mica undercut Ii Out of specification -t Scrape the mica using hacksaw bladeMica undercut: 0.7 mm (0.028 in)