Chrysler 70, 75 and 85 HP Outboard Motors Service Manual OB 3438, Page 114Get this manual
BPlace contact fingers of meter test cable across any two commutator bars at side of commutatorCAdjust voltage control until needle hits highest readingDTest each commutator bar with the bar next to it until all bars have checked zero reading shows an open circuit in pair of barsBrushesReplace brushes if any are half worndamaged or cracked To replace brushes, the commutator end cap assembly must be replacedFigure 11 1Check brush spring tension Replace springs if tension is less than (40 ounces) maximum Insulated Terminal Ground TestEquipmentOhmmeter (R Scale) or 2938-1 Circuit Tracer 1Place one tester lead on insulated terminal (outside of motor frame) 2Place second tester lead on motor framemeter should indicate c:: (infinity)tester should "not" lightA meter reading or tester lighting indicates defective ground Figure 12