Mercury 225 EFI, Service Manual

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POWER TRIM - DESIGN II
Page 5B-20 90-884294 OCTOBER 2001
Manual Tilt System
If the outboard motor is to be raised or lowered manually, turn the manual release (tilt)
valve (1) counterclockwise approximately 3 turns to the full out position. When in the full
(out) position, oil in the tilt cylinder (2) can flow freely from the up side to the down side
or from the down side to the up side. The oil return line into the reservoir (3) is also open,
allowing free oil flow to either side of the tilt cylinder to accommodate the differential oil
capacities between the tilt cylinder up side and down side cavities.
When trimming the outboard in either the up or down position, with the manual tilt valve
open or leaking, little or no movement will occur. Oil pressure from the pump (4) will move
to both, the up cavity and through the manual tilt valve into the down cavity, each cavity
would have equal pressure resulting in little or no movement.
Reverse Operation
To prevent the outboard from coming up or trailing out, when shifted into reverse and/or
throttling back rapidly, oil in the trim system must be locked in a static position. This is ac-
complished by closing the:
•
up (5) pressure operated valve
•
down (6) pressure operated valves
•
trim relief valve (7)
•
trail over valve (8)
•
impact relief valves (8)
•
manual release valve (1)
Thus, not allowing oil in the system to move in either direction.