2006 Johnson SD 30 HP 4 Stroke Outboards Service Manual, PN 5006592, Page 200Get this manual
GEARCASE TRIM TAB ADJUSTMENT Wedge block of wood between propeller blade and the anti-ventilation plateInstall the propeller nut and torque to: 156 inIbs(18 Nm) If cotter pin holes in the propeller nut and propeller shaft are not aligned, tighten the nut until they are in lineDo not loosen
TRIM TAB ADJUSTMENT&CAUTION
Improper trim tab adjustment can cause difficult steering and loss of controlA 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, outboard angle, and load conditionsNo single adjustment can relieve steering effort under all speed, outboard angle, and load conditionsIf the boat pulls to the left or right when its load is evenly distributedadjust the trim tab as follows: With the engine shut OFF, loosen the trim tab boltIf the boat pulled to starboard, move the rear of the trim tab slightly to the rightIf the boat pulled to port, move the rear of the trim tab slightly to the left Tighten the trim tab bolt Test the boat and, if needed, repeat the procedure until steering effort is as equal as possible