Mercury 75 Service Manual page 369

Tilt Up
In the up mode, as the piston rod (a) extends from the
cylinder (w), the memory piston (t) clears or uncovers
the pressure relief passage. Oil from the up cavity will
enter this passage and, if required, causes the tilt re-
lief piston (s) to open the tilt pressure relief valve (r).
This valve lowers the amount of pressure available
to lift the outboard motor. With the engine in forward
gear, and at high engine rpm, the oil pressure avail-
able will not be able to overcome the propeller thrust,
limiting the trim range to below the pressure relief ori-
fice. When the engine rpm's fall or if engine is not in
forward gear, the oil pressure is available to extend
the piston rod (a) up into the tilt range.
90-830234R3 DECEMBER 1997 MID-SECTION - 5C-9