1996-2005 Suzuki DF40, DF50 Four Stroke Outboard Service Manual, Page 472Get this manual
DF4050 "K5" ('05) MODEL
INSPECTION AND SERVICING Armature and Commutator Inspect the commutator surfaceIf surface is gummy or dirty, clean with #500 grit emery paper A
Measure commutator outside diameter09900-20101: Vernier calipers Commutator outside diameter: Standard: 29.0 mm (1.14 in) Service limit: 28.0 mm (1.10 in) If measurement exceeds service limit, replace armature