1990 Johnson Evinrude 120 thru 140, 185 thru 225, 300 HP, P/N 507875, Page 177Get this manual
1131 STEPPOWER PACK TEST
it To prevent accidental starting of engine while testing, twist and remove all spark plug leads1Twist and remove all primary leads from ignition coilsf131 2Connect No.1 ignition coil primary lead to Stevens Instrument load adapter NoPL-88 red leadadapter black lead to clean engine groundIf Stevens Instrument NoPL-88 is not available, you can make an adapter using 10 ohm, 10 watt resistor Radio Shack No271-132 or equivalent3Set peak-reading voltmeter to "POS" and "500 Connect PRV meter red lead to adapter red lead and meter black lead to clean engine ground5Crank engine and observe meter Meter must show 150 volts or higher