Trim Tab Adjustment; Models Without Power Steering; Models With Power Steering - Mercury Optimax 115 Service Manual

Trim Tab Adjustment

Propeller steering torque may cause your boat to pull in one direction. This steering torque
results from your outboard not being trimmed so the propeller shaft is parallel to the water
surface. The trim tab can help compensate for this steering torque and can be adjusted
within limits to reduce any unequal steering effort.

Models Without Power Steering

Operate your boat at normal cruising speed, trimmed to desired position. Turn your boat
left and right and note the direction the boat turns more easily.
If adjustment is necessary, loosen trim tab bolt until trim tab moves freely (does not rub
against locking ridges). DO NOT strike tab to make adjustments. Make small adjustments
at a time. If the boat turns more easily to the left, move the trailing edge of trim tab to the
left. If the boat turns more easily to the right move the trailing edge of trim tab to the right.
Position trim tab in one of the locating grooves BEFORE tightening bolt to prevent dam-
age to holding mechanism. Torque bolt to 40 lb-ft (54 Nm) and retest.

Models With Power Steering

Trim tab adjustment is not required. The trailing edge of the trim tab should be set straight
back.
90-855347R1 JANUARY 1999
OUTBOARD MOTOR INSTALLATION
Page 1D-17