1997 Johnson Evinrude "EU" 40 thru 55 2-Cylinder Service Manual, P/N 507265, Page 289Get this manual
Cranking Discharge Method 1Check battery voltage If voltage is greater than 12.5 volts, go to Step If voltage is less than 12.5 volts, go to Step 32Separate the ignition charge coil connector(s)Crank engine in short bursts until battery voltage is less than 12.5 voltsCheck battery voltage with key in the OFF position INote Disconnect
this check
engine battery cables before proceeding with
3Connect to 40 amp ammeter in series between the rectifier regulator red lead and the battery side of the starter solenoid4Reconnect the engine's battery cablesReconnect the ignition charge coil connector(s)