2003 Johnson ST 6/8 HP 4 Stroke Outboards Service Manual, PN 5005471, Page 71Get this manual
IGNITION TEST EQUIPMENT
TEST EQUIPMENT
General Information
Many ignition testers are available from various manufacturersIn addition, some automotive testers having the proper specifications can be usedDetailed instructions for the use of any tester are provided with the unit; therefore, only general information is given hereRefer to the manual of the ignition tester being used for coil specificationsSpecifications will vary among testersIgnition coils must be removed from the powerhead for power and leakage testing
Peak-reading Voltmeters
Peak-reading voltmeters are used to measure power pack output to ignition coilsVarious models available: Merc-O-Tronic Number 781 Stevens Number CD-77 Electro-Specialties Number PRV-1