2006 Johnson SD 30 HP 4 Stroke Outboards Service Manual, PN 5006592, Page 75Get this manual
ENGINE CONTROL IGNITION TESTS
IGNITION TESTSWARNING
Secondary Side
Remove the spark plug cap from the high tension cord Connect an ohmmeter between the black ignition coil lead wire and the high tension cordIf the measurement is out of specification, replace the ignition coilSecondary Ignition Coil Resistance Test Tester probe connection Red (+) Black (-) Black Resistance 4.8 to 7.2 kilohms High tension cord
Before working on or removing any electrical parts, disconnect the battery cables at the battery to prevent electrical sparksTwist and remove all spark plug leads to avoid accidental startingAll cranking output tests must be performed with spark plugs installed and torqued in the cylinder head If it is necessary to remove the spark plugs, be sure to keep the spark tester away from open spark plug holes