2004 SR Johnson 2-stroke 40, 50HP Service Manual, Page 119Get this manual
IGNITION IGNITION SYSTEM TESTS Adjust voltmeter to setting listed in following chartStart engine and run it under load at RPM where ignition problem existsMeter must show at least: Model 4Amp 12 Amp Voltmeter POS500 POS500 Output 175 175 Adjust voltmeter to settings listed in following chartCrank engine and observe meterAt minimum of 1S0 RPM, meter must show at least: Model 4Amp 12Amp Voltmeter POS500 POSSOO Output 150V 150 RPM 150V 1S0 RPM
After testing number ignition coil, test the number ignition coil If either cylinder shows less than specified output, go to Charge Coil Tests on p120 If charge coil tests good, replace the power packRemove terminal extendersInstall ignition coil primary leadsObserve proper wire routingOrangeblue primary lead must be connected to the number ignition coil
Cranking Output Test
Twist and remove primary leads from ignition coilsConnect Number ignition coil primary lead to Stevens Number PL-88 Load Adapter, P S07983, red leadConnect adapter black lead to clean engine groundIf Stevens NoPL-88 is not available, you can make an adapter using 1O-ohm, 10-watt resistor, Radio Shack No271-132, or equivalentConnect peak-reading voltmeter red lead to adapter red lead and meter black lead to clean engine ground