Yamaha F 25 Manual

Operation
26
EMU27872Adjusting 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...

Operation
27
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
the bow is greatly increased, heightening the
danger of “bow steering” and making opera-
tion difficult and dangerous.
NOTE:
Depending on the type of boat, the outboard
motor trim angle may have little effect on the
trim of the boat when operating.
EMU27921
Tilting...

Operation
28
EMU27964Procedure for tilting up (manual tilt 
models)
1. Place the gear shift lever in neutral (if
equipped) and face the outboard motor
forward.
2. On full-pivot system models, tighten the
steering friction adjuster by turning it
clockwise to prevent the motor from turn-
ing freely.
3. Tighten the air vent screw. On models
equipped with a fuel joint, disconnect the
fuel line from the outboard motor.
4. Close the fuel cock.5. Tilt support bar equipped models: Hold
the rear of the top...

Operation
29
locked position. If the tilt support lever/bar
does not automatically lock, swing the motor
a little to the left and right.
EMU28032Procedure for tilting down (manual tilt 
models)
1. Slightly tilt the outboard motor up.
2. If equipped with the tilt support bar: Slow-
ly tilt the outboard motor down while pull-
ing the tilt support bar lever up.
3. If equipped with the tilt support knob: Pull
the knob out, and then slowly tilt the out-
board motor down.
4. If equipped with the tilt support...

Maintenance
30
EMU31480
Specifications
NOTE:
“(AL)” stated in the specification data below
represents the numerical value for the alumi-
num propeller installed.
Likewise, “(SUS)” represents the value for
stainless steel propeller installed and “(PL)”
for plastic propeller installed.
EMU28218
Dimension:
Overall length:
623 mm (24.5 in)
Overall width:
345 mm (13.6 in)
Overall height S:
1021 mm (40.2 in)
Transom height S:
432 mm (17.0 in)
Weight (AL) S:
17.0 kg (37 lb)
Performance:
Full throttle operating...

Maintenance
31
EMU28222
Transporting and storing out-
board motor
WARNING
EWM00690

Leaking fuel is a fire hazard. When trans-
porting and storing the outboard motor,
close the air vent screw and fuel cock to
prevent fuel from leaking.

USE CARE when transporting fuel tank,
whether in a boat or car.

DO NOT fill fuel container to maximum
capacity. Gasoline will expand consider-
ably as it warms up and can build up
pressure in the fuel container. This can
cause fuel leakage and a potential fire
hazard....

Maintenance
32
NOTE:
Place a towel or something similar under the
outboard motor to protect it from damage.
EMU28241Storing outboard motor
When storing your Yamaha outboard motor
for prolonged periods of time (2 months or
longer), several important procedures must
be performed to prevent excessive damage.
It is advisable to have your outboard motor
serviced by an authorized Yamaha dealer pri-
or to storage. However, you, the owner, with a
minimum of tools, can perform the following
procedures.
CAUTION:...

Maintenance
33
CAUTION:
ECM00300
Do not run the engine without supplying it
with cooling water. Either the engine water
pump will be damaged or the engine will
be damaged from overheating. Before
starting the engine, be sure to supply wa-
ter to the cooling water passages.
CAUTION:
ECM00290
If the fresh water level is below the level of
the anti-cavitation plate, or if the water
supply is insufficient, engine seizure may
occur.
6. Cooling system flushing is essential to
prevent the cooling system from...

Maintenance
34
NOTE:
For cooling system flushing instructions, see
page 31.
EMU28460Checking painted surface of motor
Check the motor for scratches, nicks, or flak-
ing paint. Areas with damaged paint are more
likely to corrode. If necessary, clean and paint
the areas. A touch-up paint is available from
your Yamaha dealer.
EMU28486
Periodic maintenance
WARNING
EWM01070
Be sure to turn off the engine when you
perform maintenance unless otherwise
specified. If you or the owner is not famil-
iar with...

Maintenance
35
EMU28522Maintenance chart
Frequency of maintenance operations may be adjusted according to the operating conditions,
but the following table gives general guidelines. Refer to the sections in this chapter for expla-
nations of each owner-specific action.
NOTE:
When operating in salt water, turbid or muddy water, the engine should be flushed with clean
water after each use.
The “” symbol indicates the check-ups which you may carry out yourself.
The “” symbol indicates work to be carried out...