1994 Johnson/Evinrude Outboards 40 thru 55 Service Manual, Page 118Get this manual
Power Test
Do not exceed the coil's maximum specified amperage when testing it
f41 The ignition coil is tested with "normal" polarity connectionsConnect tester red lead to the primary terminal of the coil and the tester black lead to the ground tab Connect the high tension lead of the tester to the coil spark plug lead steady spark in the tester, at or before maximum specified amperage, indicates good coilRefer to Ignition Coil SpecificationsSurface Leakage Test Do not exceed the coil's maximum specified amperage when testing itThe ignition coil and spark plug lead should be tested for leakage and insulation failures using the ignition testerLeakage is caused by moisture, cracks, or holes in the coil housing or spark plug leadsr;;] With the tester's small black and red leads still connected, remove the tester's high tension lead from the coilTurn on the tester and probe entire surface of the coil, spark plug lead, and spark plug coverLeakage will be apparent wherever insulation has broken downReplace any coil or spark plug lead that shows leakage