1991 Johnson/Evinrude EI 60 thru 70 outboards Service Manual, Page 218Get this manual
Trim Tab Adjustment The boat may be slightly easier to steer in one direction or the other due to steering forces or other reasonsTo check this, run the boat in straight line with balanced load in an area where current and wind will not be factor single trim tab adjustment will only relieve steering effort under one set of speed, trim and loading conditionsNo single setting can relieve steering effort under all speed, trim and loading conditions1Turn the steering wheel in both directions to determine the direction that requires the least amount of steering effort2Loosen the trim tabIf the boat pulls to port, move the rear of the trim tab to port pulls to starboard, move the rear of the trim tab to starboard3Reference numbers, thru 6, are embossed on the trim tab for ease of adjustmentAlign the reference number with the recessed screw or the embossed line4Retighten trim tab screw and recheck steering effort in both directionsRepeat procedure until steering effort is equal in both directions5After final adjustment, tighten the trim tab screw to the following torque :