1998 Johnson Evinrude EC 50 thru 70 HP 3-Cylinder Service Manual, Page 225Get this manual
Trim Tab Adjustment
Improper trim tab adjustment can cause difficult steering
A propeller will generate steering torque when the propeller shaft is not running parallel to the water's surfaceThe trim tab is adjustable to compensate for this steering torqueA single trim tab adjustment will relieve steering effort under only one set of speed, motor angle, and load conditionsNo single adjustment can relieve steering effort under all speed, motor angle, and load conditionsIf the boat pulls to the left or right when its load is evenly distributed, adjust the trim tab as follows:
Important
IJJ With the motor shut OFF, loosen the trim tab screwIf