1988 Johnson Evinrude CC 60 thru 75 outboards Service Manual, Page 66Get this manual
Maximum Spark Advance Adjustment Characteristics of this ignition system cause an automatic increase in spark advance over the basic setting as engine speed increases from approximately 3500 to 5000 RPMFor this reason the most accurate setting is made when the engine is run over 5000 RPM INotel Run the engine with the proper test wheelDo not run the
engine with propeller or flushing adapter for the adjustment1Connect timing light to the No1 cylinder2Start and run the engine to minimum of 5000 RPM in FORWARD gear3The engine timing pointer must align with correct degree mark on the flywheel grid