1997 Johnson Evinrude "EU" 90 thru 115 90 CV Service Manual, P/N 507267, Page 40Get this manual
Maximum Spark Advance
INote Ru the eng ne with the proper test wheelDo not ru the
engine with propeller or flushing' adapter for the adjustment1Install the spark plugs and connect the leadsConnect timing light to the No.1 cylinder2Start and run the engine at full throttle in FORWARD gear with the timer base fully advanced
3The engine timing mark must align with the correct degree
mark on the flywheel gridSee chart below
Maximum Spark Advance
PCE0026
4Stop the engine to prevent contact with rotating partsTo adjust: Loosen the locknut on the spark advance rod
Rotate the thumb wheel to correct the timingRotate top of thumb wheel toward the crankcase to advance the timingRotate top of thumb wheel away from the crankcase to retard the timing Tighten the locknut and repeat Steps and 3