1998 Johnson Evinrude "EC" 9.9 thru 30 HP 2-Cylinder Outboards Service Manual, Page 131Get this manual
STEP.6RUNNING OUTPUT TEST
1Twist and remove primary leads from ignition coils
2Use clockwise twist to install Stevens NoTS-77 terminal extenders, or equivalent, on ignition coil primary posts3Install primary leads on terminal extendersObserve proper wire routingOrangeblue primary lead must be connected to the No ignition coilmoving engine parts
INote Route all tester leads so they do not interfere with
4Connect peak-reading voltmeter red lead to No.1 terminal extenderConnect meter black lead to clean engine ground5Adjust voltmeter to setting listed in following chartStart engine and run it under load at RPM where ignition problem existsMeter must show at least: