1994 Johnson/Evinrude Outboards 40 thru 55 Service Manual, Page 46Get this manual
Maximum Spark Advance Run the engine with the correct test propellerDo not run the engine with regular propeller or flushing adapter for this adjustment1Connect timing light to the No.1 spark plug leadMark the flywheel timing grid at 19 BTDC2Start the engine and allow it to reach normal operating temperature3Run the engine at no less than 5000 RPM in FORWARD gearThe engine's timing pointer must align with 19 BTDC on flywheel's timing grid G2l '"
i partsAdjust the length of the spark control rodif necessary, by removing the forward socket from spark lever
4Stop the engine to prevent contact with rotating