I purchased a used 1988 Ranger R80 with a Mercury Optimax 150. After using all spring and summer I have noticed that I have to turn the steering more and more to get the motor to turn.
Check the large nut that holds the cable to the tilt-tube on engine. Have someone move the wheel while watching that area. If the cable sheath is moving inside the nut, the nut is not tightened fully. The cable sheath should not be moving.