1971 Johnson 60HP outboards Service Manual, Page 35Get this manual
Check all Wlrlng associated with the system for any loose or corroded terminal connections and plug-in connectionsMake sure of clean, tight connection from the negative (-) terminal of the ignition coil to the groundAlso check for clean, tight battery ground cable connectionProbe all high tension leads for cracked or damaged insulationThe high tension leads should also be checked with an ohmmeter to locate any excessive reSistance or opensCheck for correct battery polarity (negative ground)Make sure battery cable connections are clean and tightFigure 4-5Checking Voltage at Amplifier 3SPARK PLUGSThe spark plugs should be removed and examined
If the center electrode has worn to point, it should be replaced