1998 Johnson Evinrude "EC" 9.9 thru 30 HP 2-Cylinder Outboards Service Manual, Page 299Get this manual
Description of Charging System The outboard charging system consists of battery, flywheel, an alternator stator, and rectifierThe engine's battery can affect the charging system operationThe battery should be of heavy-duty marine construction, should be the correct capacity for the application, and should be in good condition with normal charge
engine's flywheel contains the permanently charged magnets which provide the energy to power the stator windingsThe magnets must be at their original design strength for full alternator output
The alternator stator consists of many windings of wire wrapped around metal laminationsThe stator is attached to the ignition plateThe flywheel's magnetic lines of force cutting through the stator windings produce alternating currentThe stator or its leads could be damaged which could result in reduced or no alternator output