1990 Johnson Evinrude "ES" 40 thru 55, P/N 507872, Page 121Get this manual
IGNITION OUTPUT TESTS ill plugs installed and torqued in the cylinder headIf necesAll cranking output tests must be performed with spark sary to remove the spark plugs, be sure to keep the spark tester away from open spark plug holes
The following series of steps will systematically isolate problem area in the ignition systemTo reduce your troubleshooting time and to avoid incomplete results, perform these steps in the order written
STEPTOTAL OUTPUT TEST
f11 1Twist and remove the spark plug leads from both spark plugsf21 2Adjust the gap on the spark tester to V2 in(12 mm)Connect l=.J tester leads to the spark plug leadsSecure tester clip to clean engine groundTo prevent possible arcing of high voltage, route tester leads at least in(51 mm) from any metal surface
i or spark tester during cranking tests