Johnson Evinrude Outboard Motors 1956-1970 1.5-40hp repair manual., Page 224Get this manual
ELECTRICAL
or the meter indicates continuity, the armature is grounded and MUST be replacedChecking the Commutator Bar 7- Check between or check bar-to-bar as shown in the accompanying illustrationThe test light should light, or the meter should indicate continuityIf the commutator falls the test, the armature MUST be replacedTurning the Commutator 8- True the commutator, if necessary, in latheNEVER undercut the mica because the brushes are harder than the insulationUndercut the insulation between the commutator bars 132" to the full width of the insulation and flat at the bottomA triangular groove is not satisfactoryAfter the under-cutting work is completed, clean out the slots carefully to remove dirt and copper dustSand the commutator lightly with No00 sandpaper to remove any burrs left from the undercuttingCheck the armature second time on the growler for possible short circuitsPositive Brushes 9- The positive brushes can always be identified as the brush with the lead connected to the field coilObtain an ohmmeterConnect one lead of the meter to the end of the brush and the other lead to the terminalThe ohmmeter MUST indicate continuity between the brush and the terminalIf the meter indicates any resistance, check the lead to the brush and the lead to the positive terminal AC MILLIAMMETER