2002/2003 Johnson SN/ST 2 Stroke 3.5, 6 8 HP Outboards Service Manual, PN 5005466, Page 81Get this manual
IGNITION IGNITION TESTS3.5
Power Pack Cranking Output Test
IMPORTANT: To prevent accidental starting of engine, twist and remove spark plug lead from the spark plugAttach to spark testerSet peak-reading voltmeter to "POS" and "500 Twist and pull the primary lead off the ignition coilInstall terminal extender on the primary terminal by twisting in clockwise directionAttach the primary lead to the terminal extenderTo test the power pack output, connect the meter black lead to clean engine groundConnect the meter red lead to metal part of extender on ignition coilCrank the engine and observe the meter reading
to clean engine groundCrank the engine and observe the meter reading