1990 Johnson Evinrude 120 thru 140, 185 thru 225, 300 HP, P/N 507875, Page 144Get this manual
STEPRUNNING OUTPUT TEST
1Twist and remove all primary leads from ignition coilsf151 2in install terminal extenders Stevens Instrument NoTS-77 or to Ignition cOil primary postsInstall primary leads on terminal extenders
INotel Route all tester leads so they do not interfere with moving engine parts4Set peak-reading voltmeter to "POS" and "500 f151 5Connect PRY meter red lead to No.1 terminal extenderConnect meter black lead to clean engine 6Start engine and run under load at RPM where ignition problem exists Meter must show 180 volts or higher7Repeat Steps and for remaining cylinders If one or more cylinders show low output, go to STEPCHARGE COIL TEST If one or more cylinders show no output, go to STEPSENSOR COIL TEST8Remove TS-77 extenders and install ignition coil primary leadsObserve proper wire routingRefer to Page 3-18