1997 Johnson Evinrude "EU" 90, 105RW, 115, 150, 150W, 175 60 LV Service Manual, P/N 507268, Page 281Get this manual
Cleaning and Inspection
1Inspect the brushes; replace if damaged, cracked, or one-half wornReplace brush springs, if weak
2Clean the commutator with 300-grade emery clothIf commutator surface is unevenly worn or pitted, turn it on latheRemove any trace of oil or metal dust from commutator
3Check the armature on growler for shorted turnsCheck for grounding by using test light or meterInspect armature insulation for indications of overheating or damaged windingsClean off any carbon deposits or foreign matter which may contribute to later windings failure4Check permanent magnetsMagnets should strongly attract any steel or iron object held inside frameWeak magnets could cause excessive RPM on No Load Current Draw, Electric Starter test5If the pinion does not properly engage the flywheel, the pinion and shaft may be worn, distorted, or dirty6Inspect and replace end cap thrust washer if distorted or worn excessively7Inspect and replace armature shaft snap ring if worn or distorted