1988 Johnson Evinrude CC 60 thru 75 outboards Service Manual, Page 148Get this manual
Step 2Sensor Coil Running Tests Using C.DVoltmeter and Adapter Sensor Coil Output TestSeparate the four-wire connector and plug both ends into the adapterSet the voltmeter switches to "S" and "5 If using Merc-O-Tronic Model 781 voltmeter, set the switches to "POS" and "5 Turn all adapter switches ON
INote engmeall tester leads so they do not interfere with moving Rou.te partsAPlace the meter black lead in jack "D Place the meter red lead in jack "A Start the engine and run at RPM where problem existsObserve the meterStop the engine