Adjusting Boat Trim - Yamaha F8 Owner's Manual

Operation
1. Trim rod
3. Reposition the rod in the desired hole.
To raise the bow ("trim-out"), move the rod
away from the transom.
To lower the bow ("trim-in"), move the rod to-
ward the transom.
Make test runs with the trim set to different an-
gles to find the position that works best for
your boat and operating conditions.
EWM00400
WARNING
Stop the engine before adjusting the
●
trim angle.
Use care to avoid being pinched when
●
removing or installing the rod.
Use caution when trying a trim position
●
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.
TIP:
The outboard motor trim angle can be
changed approximately 4 degrees by shifting
the trim rod one hole.
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-
44
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.
Bow Down
Too much trim-in causes the boat to "plow"
through the water, decreasing fuel economy
and making it hard to increase speed. Operat-
ing with excessive trim-in at higher speeds
also makes the boat unstable. Resistance at