1997 "EU" Johnson Evinrude 5 thru 15 Four Stroke Service Manual, P/N 507262, Page 311Get this manual
Cleaning and InspectionAll Models
1Inspect the brushes; replace if one-half worn, damaged, or crackedReplace brush springs, if weak2Clean commutator with 300 grade emery clothIf commutator surface is unevenly worn or pitted, turn on latheRemove any trace of oil or metal dust from the commutator
m 3Check grounding by usinga agrowler for shortedInspect the armature on turnsCheck armature for test light or meter
armature insulation for indications of overheating or damaged windingsClean off any deposits of carbon or foreign matter which may contribute to later failure of the windings4Check magnetsMagnets should strongly attract steel or iron objects held inside the frameWeak magnets cause excessive RPM on No Load Current Draw, Electric Starter test