Mercury 300 XS OptiMax Manual page 93

With most boats, operating around the middle of the trim range will give
satisfactory results. However, to take full advantage of the trimming capability,
there may be times when you choose to trim your outboard all the way in or
out. Along with an improvement in some performance aspects comes a greater
responsibility for the operator, and this is being aware of some potential control
hazards. The most significant of which is a pull or torque, which can be felt on
the steering wheel. This steering torque results from the outboard being
trimmed so that the propeller shaft is not in a horizontal position.
TRIM IN PIN (THREE-RAM)
Operating the boat at high speeds with the outboard trimmed too far under
can create excessive bow steer, resulting in the operator losing control of the
boat. Install the trim limit pin in a position that prevents excessive trim under
and operate the boat in a safe manner.
Some boats, particularly some bass boats, are built with a greater than normal
transom angle, which will allow the outboard to be trimmed further in or under.
This greater trim under capability is desirable to improve acceleration, reduce
the angle and time spent in a bow high boat during planing off, and in some
cases, may be necessary to plane off a boat with aft live wells, given the variety
of available propellers and height range of engine installations.
However, once on plane, the engine should be trimmed to a more intermediate
position to avoid a bow‑down planing condition called plowing. Plowing can
cause bow steering or oversteering and inefficiently consumes horsepower.
Stainless Steel Tilt Pin
The owner may decide to limit the trim in. For standard models, purchase a
stainless steel tilt pin from your dealer and insert it in whatever adjustment hole
in the transom brackets is desired.
eng
MAINTENANCE
WARNING
!
a - Tilt pin (not included with engine)
a
2688
2749
87
17‑ 49930A 1
Limits the down trim angle of the power
trim equipped engines, or aids in
determining the trim out angle on
non‑power trim engines.