1998 Johnson Evinrude EC 50 thru 70 HP 3-Cylinder Service Manual, Page 121Get this manual
Indexing Flywheel, Erratic Ignition Internal power pack problems could cause module to fire erratically or continuouslyTo troubleshoot this situation, you must determine that each cylinder is firing at the correct time and no more than once per revolution1Disconnect the spark plug leads and remove all spark plugs