1988 Johnson/Evinrude "CC" 40 thru 55 Models Service Manual, Page 154Get this manual
1141 Step 3Power Pack Running Test Using .D Voltmeter
f141 Set the voltmeter switches to-" and "500 Twist and pull l:!.J the primary leads off the ignition coils Turning in clockwise direction, attach terminal extenders to the primary terminal of the ignition coils Reconnect the primary leads to the terminal extendersObserve wire routing and ignition timingorange blue lead to the No.1 (top) ignition coil
all tester leads so they do not interfere with moving engine parts
ATo test power pack output, connect the meter black lead to clean engine groundStart the engine and run at RPM where problem existsBHold the meter red lead against metal part of the No1 coil extenderDo not hold metal part of meter red lead when the engine is operating