2004 SR Johnson 2-stroke 40, 50HP Service Manual, Page 118Get this manual
IGNITION IGNITION SYSTEM TESTS
IGNITION SYSTEM TESTS
CAUTION
All cranking output tests must be performed with spark plugs installed and torqued in the cylinder headIf necessary to remove the spark plugs, be sure to keep the spark tester away from open spark plug holesCheck Total Ignition Output Test to find the specific fault symptomLocate the specific fault on the Troubleshooting Flowchart on p115Follow the test sequence in the chart
If equipped, install the emergency stop switch clip and lanyard assemblyCrank the engineSpark should jump each tester gap alternately If tester shows good output on both cylinders, go to Running Output Test If tester shows good output on one cylinder, go to Cranking Output Test on p118 If tester shows no output, go to Stop Circuit Tests on p118
IMPORTANT: It is possible for the ignition system to have problem but still produce good outputIf the engine "pops" or "backfires" during starting, the ignition may be out of timeCheck the following: Coil primary wire routing Spark plug lead routing Flywheel and key condition and location Synchronization and linkage adjustments