2004 SR Johnson 2-stroke 40, 50HP Service Manual, Page 120Get this manual
IGNITION
IGNITION SYSTEM TESTS
Crank engine and observe results at spark tester If there is no spark at one gap, go to Cranking Output Test on p118 If there is no spark at both gaps, go to Charge Coil Tests on p120 If the spark jumps alternately at each gap, the problem is in the stop circuitGo to Stop Button Ohmmeter Test and Key Switch Ohmmeter TestStop Button Ohmmeter Test IMPORTANT: All ohmmeter tests must be performed with the engine NOT runningInstall the clip and lanyardDisconnect the 5-pin Amphenol connector between the power pack and ignition plateConnect meter leads between ignition plate connector, terminal "E," and clean engine ground The meter must show high readingKey Switch Ohmmeter Test STEP IMPORTANT: All ohmmeter tests must be performed with the engine NOT runningInstall the clip and lanyardDisconnect the 5-pin Amphenol connector between the power pack and ignition plateConnect meter leads between ignition plate connector, terminal "E," and clean engine ground Key OFF, meter must show low reading Key ON, meter must show high readingSTEP If in STEP 1, key ON reading is low one, disconnect harness blackyellow lead from key switch "M" terminal If meter now shows high reading, replace key switch If meter shows low reading, go to STEP 3STEP Disconnect the key switch 6-pin connector If meter now shows high reading, repair or replace key switch harness If meter shows low reading, go to STEP 4STEP Disconnect the engine harness to instrument harness 6-pin connector that contains the blackyellow lead If meter now shows high reading, repair or replace instrument harness If meter shows low reading, repair or replace engine harness If the engine fails to shut off, test for open black yellow lead, blackwhite lead, damaged key switch, or damaged power pack