1987-1993 Mercury Mariner Outboards 70/75/80/90/100/115HP 3 and 4-cylinder Factory Service Manual, Page 284Get this manual
CAUTION Disconnect battery cables at battery before removing power trim wires from solenoids3Disconnect power trim wires at solenoids (BLUE, GREEN, and BLACK)4Open filler cap and release any remaining pressure in the system
5Remove outboard transom mounting bolts, and loosen tilt tube nut until nut is flush with end of tilt tube thread
51375 51339Filler CapTransom Mount Bolts (2)Tilt Tube Nut (flush with end of thread)