Checking Trim System Fluid Level; Trimming (Models With Power Trim); Trimming Outboard "Out" ("Up"); Trimming Outboard "In" ("Down") - Mercury 45 Jet 50-55 Service Manual

CHECKING TRIM SYSTEM FLUID LEVEL

IMPORTANT: This trim system is pressurized. Remove
fill screw when outboard is trimmed to the full "up" po-
sition. Retighten fill screw securely.
1. Trim outboard to full "up" position. Engage tilt lock lever
(a). Trim system fluid can only be checked when out-
board is in this position.
a
2. Remove fill screw and check fluid level. Fluid level
should be to bottom of threads in fill hole (b).
3. If necessary, add Quicksilver Power Trim & Steering
Fluid or; Automatic Transmission Fluid (ATF) Type F,
FA or Dexron II fluid to trim system.
4. Reinstall fill screw.

Trimming (Models with Power Trim)

NOTE: Because varying hull designs react differently in
various degrees of rough water, it is recommended to ex-
periment with trim positions to determine whether trimming
up or down will improve the ride in rough water.
When trimming your outboard from a mid-trim position (trim
tab in neutral straight fore-and-aft position), you can expect
the following results:
90-817643R1 DECEMBER 1996
TRIMMING OUTBOARD "OUT" ("UP") CHARACTER-
ISTICS
WARNING
!
Excessive trim "out" also may reduce the stability of
some high speed hulls. To correct instability at high
speed, reduce the power GRADUALLY and trim the
outboard "in" slightly before resuming high speed op-
eration. (Rapid reduction in power will cause a sudden
change of steering torque and may cause additional
momentary boat instability.)
1. Will lift bow of boat, generally increasing top speed.
2. Transfers steering torque harder to left on standard or
slightly elevated transom installation (single out-
board).
3. Increases clearance over submerged objects.
4. In excess, can cause porpoising and/or ventilation.
5. If trimmed out beyond the water pickup, reduced water
supply can cause serious overheating.

TRIMMING OUTBOARD "IN" ("DOWN")

CHARACTERISTICS
WARNING
!
50157
Excessive speed at minimum trim "in" may cause un-
desirable and/or unsafe steering conditions. Each
boat should be tested for handling characteristics af-
ter any adjustment is made to the trim angle (trim ad-
justment pin relocation).
1. Will help planing off, particularly with a heavy load.
2. Usually improves ride in choppy water.
3. In excess, can cause boat to veer to the left or right
(bow steer).
4. Transfers steering torque harder to right (or less to the
left) on single outboard installations.
5. Improves planing speed acceleration.
GENERAL INFORMATION and SPECIFICATIONS - 1-11