Yamaha F25 - Manual (Page 31)

Operation
26
EMU27872
Adjusting trim angle for manual tilt
models
There are 4 or 5 holes provided in the clamp
bracket to adjust the outboard motor trim an-
gle.
1.
Stop the engine.
2. Tilt the outboard motor up, and then re-
move the trim rod from the clamp bracket.
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.
WARNING
EWM00400
● 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.
NOTE:
The outboard motor trim angle can be
changed approximately 4 degrees by shifting
the trim rod one hole.
EMU27911
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. The trim tab can
also be adjusted to help offset this effect.
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.
1. Trim rod
U69M15E0.book Page 26 Wednesday, April 5, 2006 4:48 PM