2003 Johnson ST 6/8 HP 4 Stroke Outboards Service Manual, PN 5005471, Page 74Get this manual
IGNITION SYSTEM TESTS Remove terminal extendersInstall ignition coil primary lead
Stop Circuit Test
Cranking Output Test
Set peak-reading voltmeter to "POS" and "500 Twist and remove primary lead from ignition coilConnect ignition coil primary lead to Stevens NoPL-88 load adapter red leadConnect adapter black lead to clean engine groundIf Stevens NoPL-88 is not available, you can make an adapter using 10-ohm, 10-watt resistor, Radio Shack No271-132, or equivalentConnect peak-reading voltmeter red lead to adapter red lead and meter black lead to clean engine ground
CAUTION
To avoid possible shock hazard, do not handle ignition coils or spark tester during cranking tests
Elimination Test
Disconnect Amphenol connector between stop circuit and power pack