1996-2005 Suzuki DF40, DF50 Four Stroke Outboard Service Manual, Page 387Get this manual
13-51 DF40DF50 "K1" (01) model INSPECTIONSERVICING Pinion Inspect pinionReplace pinion if damaged or worn Armature and Commutator Inspect the commutator surfaceIf surface is gummy or dirty, clean with 400 grade emery paper A
A Measure commutator outside diameter09900-20101Vernier calipers Commutator outside diameter: Standard33.0mm (1.30 in) Service limit32.0mm (1.26 in) If measurement exceeds service limit, replace armature