2001 Mercury Mariner 50-60HP Factory Service Manual, Page 333Get this manual
POWER TRIM
Manual Tilt
To manually tilt the outboard engine, the owner will need to back out the manual release valve (p) 3-4 turnsWith the valve backed out, the internal passages inside the manifold are connected togetherThese passages connect both the cylinder down and up cavities together, along with the reservoir, allowing the engine to be raised or loweredPiston rod (a) movement will continue until the manual release valve (p) is closed, locking the fluid inside of the cylinder and manifold