1991 Johnson/Evinrude EI Outboards 2.3 thru 8 Service Manual, Page 102Get this manual
Surface Leakage -
An Models
Do not exceed the coil's maximum specified amperage when testing the coilThe 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 leadsthe tester's small black and red leads still connected, remove the tester's spark plug lead from the coilTurn on the tester and probe entire surface of the coil, spark plug lead and spark plug coverFlashover will be apparent wherever insulation has broken downReplace any coil or spark plug lead that shows leakage