1988 Johnson/Evinrude "CC" 40 thru 55 Models Service Manual, Page 241Get this manual
Trim Tab AdjustmentAll Models 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
A 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 effort