1980 Johnson 4HP Service Manual, Page 43Get this manual
Resistance 01 the primary winding should 0.1 0.05 ohmsfCalibrate the ohmmeter to high ohm scalethen connect the meter red lead (+) to the" terminal jumper wireConnect the meter bIack lead (-) to the terminal inside the high tension lead coverSee Figure 4-29 general information is given hereSee Coil Speci1icationsSection 2IGNITION COIL TESTING (IGNITION COIL MUST REMOVED FROM POWER FOR POWER AND LEAKAGE TESTING
'SAFETY WARNING
avoid possibIe shock hazards and to prevent leakage, perform all tests to the coil wooden insulated bench topIf the ignition coil is goodthe tester's meter will fall within the good with the primary circuit adjusted as speci1iedConnect the test leads the ignition tester to the coilConnect the bIack lead of the tester to the orange lead 01 the ignition coil and the tester's red lead to the coils orange bIack stripe ground leadConnect the high tension lead of the tester to the high tension lead (secondary) 01 the ignition coil With the tester set to coil index operating amperageMerc-O-Tronic illust ratedadjusted as speci1iednote meter readingSee Figure 4-30 low reading the tester indicates weak coil which must re placed dead coil will show reading