1992 Johnson Evinrude "EN" 40 thru 55 Service Manual, P/N 508143, Page 129Get this manual
7 STEPIGNITION PLATE OUTPUT TEST
it To prevent accidental starting of engine while testing, twist and remove both spark plug leads1Twist and remove primary leads from ignition coils
I!J Connect adapter black lead to clean engine ground
rJl 2Connect No.1 ignition coil primary lead to Stevens Instrument load adapter NoPL-88 red leadIf Stevens Instrument NoPL-88 is not available, you can make an adapter using 10-ohm, 10-watt resistor, Radio Shack No271 -132, or equivalent
3Set peak-reading voltmeter to "POS" and "500"
Connect voltmeter red lead to adapter red lead and meter black lead to clean engine ground