1998 Johnson Evinrude "EC" 25, 35 HP 3-Cylinder Outboards Service Manual, Page 202Get this manual
W With the motor shut OFF, loosen the trim tab screw If the boat pulled to the right, move the rear of the trim tab slightly to the rightIf the boat pulled to the left, move the rear of the trim tab slightly to the left Tighten the trim tab screw to 60-84 inIbs(7-9 Nm) Test the boat and, if needed, repeat the procedure until steering effort is as equal as possibleHigh motor installationsThe trim tab might be above the water when the motor is trimmed outSteering effort might increaseSteering effort will be reduced if you trim the motor in and submerge the trim tabDual motorsMove both trim tabs equally and in the same direction