1997 Johnson Evinrude "EU" 90, 105RW, 115, 150, 150W, 175 60 LV Service Manual, P/N 507268, Page 128Get this manual
Output Tests
cranking output tests must be performed with spark plugs installed and torqued in the cylinder headIf necessary to remove the spark plugs, be sure to keep the spark tester away from open spark plug holes
STEPTOTAL OUTPUT TEST
To avoid electrical shock, do not handle ignition coils or spark tester during cranking tests1Twist and remove all spark plug leads
2Adjust the gap on the spark tester to 7 16 in(11 mm)Connect tester leads to the spark plug leadsSecure tester clip to clean engine ground(51 mm) from any metal surface
INote To prevent high voltage arc, route tester leads at least in3If equipped, install the clip onto the emergency stop switch Crank the engineSpark should jump each tester gap alternately4Refer to Troubleshooting Sequence Chart, Page 3-24Start with your specific fault symptom and continue troubleshooting in sequence