Adjusting Trim Angle (Power Tilt Models); Adjusting Boat Trim - Yamaha F9.9F Owner's Manual

EMU27904
Adjusting trim angle (power tilt mod-
els)
EWM00753
WARNING
Be sure all people are clear of the out-
G
board motor when adjusting the trim an-
gle. Body parts can be crushed between
the motor and the clamp bracket when
the motor is trimmed or tilted.
Use caution when trying a trim position
G
for the first time. Increase speed gradu-
ally and watch for any signs of instability
or control problems. Improper trim an-
gle can cause loss of control.
If equipped with a power trim and tilt
G
switch located on the bottom cowling,
use the switch only when the boat is at a
complete stop with the engine off. Do
not adjust the trim angle with this switch
while the boat is moving.
Tilt the engine to the desired angle using the
power tilt switch.
TIP:
Stay within the trim operating angle when
trimming the outboard motor using the power
tilt system.
To raise the bow ("trim-out"), tilt the engine up.
To lower the bow ("trim-in"), tilt the engine
down.
Make test runs with the trim set to different an-
gles to find the position that works best for
your boat and operating conditions.
EMU27912

Adjusting boat trim

When the boat is on plane, a bow-up attitude
results in less drag, greater stability and effi-
ciency. This is generally when the keel line of
the boat is up about 3 to 5 degrees. With the
bow up, the boat may have a greater tenden-
cy to steer to one side or the other. Compen-
sate for this as you steer. When the bow of the
boat is down, it is easier to accelerate from a
standing start onto plane.
Bow Up
Too much trim-out puts the bow of the boat
too high in the water. Performance and econ-
omy are decreased because the hull of the
boat is pushing the water and there is more air
drag. Excessive trim-out can also cause the
propeller to ventilate, which reduces perfor-
mance further, and the boat may "porpoise"
(hop in the water), which could throw the op-
erator and passengers overboard.
Operation
45