1985 OMC 65, 100 and 155 HP Models Commercial Service Manual, PN 507450-D, Page 161Get this manual
Power Pack Output Test 1Remove four-wire connectors from adapter and reJoinSeparate the four-wire connector between power pack and ignition coils and plug into adapter
2Set meter switches to Negative (-) and 500, with all switches
onClip black meter lead to groundStart engineRun engine at minimum of 1000 rpm, and plug red meter lead alternately into pinholes "A," "B" and "C Meter should read the voltage listed below (or higher)Power Pack Output Test
230 volts or higher 170 volts or higher
3Any voltage differences between "A," "B," and "C," turn switches to "Off" position and test alternately" A," "B," and "c" while cranking engineMeter should read the voltage listed below (or higher)No or low reading, replace packMeter does read correct voltage, check or replace ignition coilPower Pack Output Test