Yamaha F 25 Manual

							General information
6
“The general prudential rule”
This rule is called Rule 2 in the International
Rules and says,
“In obeying and construing these rules due re-
gard shall be had to all dangers of navigation
and collision, and to any special circumstanc-
es, which may render a departure from the
above rules necessary in order to avoid im-
mediate danger.”
In other words, follow the standard rules ex-
cept when a collision will occur unless both
vessels try to avoid each other. If that is the
case, both vessels become “Give-Way” ves-
sels.
EMU25520Rules when encountering vessels
There are three main situations which you
may encounter with other vessels which could
lead to a collision unless the Steering Rules
are followed:
Meeting: (you are approaching another ves-
sel head-on)
Crossing: (you are traveling across the other
vessel’s path)
Overtaking: (you are passing or being
passed by another vessel)
In the following illustration, your boat is in the
center. You should give the right-of-way to
any vessels shown in white area (you are the
Give-Way vessel). Any vessels in the shaded
area must yield to you (they are the Give-Way
vessels). Both you and the meeting vessel
must alter course to avoid each other.Meeting
If you are meeting another power vessel head
on, and are close enough to run the risk of col-
lision, neither of you has the right-of-way!
Both of you should alter course to avoid an ac-
cident. You should keep the other vessel on
your port (left) side. This rule doesn’t apply if
both of you will clear one another if you con-
tinue on your set course and speed.
Crossing
When two power driven vessels are crossing
each other’s path close enough to run the risk
of collision, the vessel which has the other on
the starboard (right) side must keep out of the
way of the other. If the other vessel is on your
right, you must keep out of its way; you are the
Give-Way vessel. If the other vessel is on
your port (left) side, remember that you
should maintain course and direction, provid-
ed the other vessel gives you the right-of-way
as it should.
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							General information
7
Overtaking
If you are passing another vessel, you are the
“Give-Way” vessel. This means that the other
vessel is expected to maintain its course and
speed. You must stay out of its way until you
are clear of it. Likewise, if another vessel is
passing you, you should maintain your speed
and direction so that the other vessel can
steer itself around you.
EMU25530Other special situations
There are three other rules you should be
aware of when driving your boat around other
vessels.
Narrow channels and bends
When navigating in narrow channels, you
should keep to the right when it is safe and
practical to do so. If the operator of a power-
driven vessel is preparing to go around a
bend that may obstruct the view of other water
vessels, the operator should sound a pro-
longed blast on the whistle (4 to 6 seconds). If
another vessel is around the bend, it too
should sound the whistle. Even if no reply is
heard, however, the vessel should still pro-
ceed around the bend with caution. If you nav-
igate such waters with your boat, you will
need to carry a portable air horn, available
from local marine supply stores.Fishing vessel right-of-way
All vessels which are fishing with nets, lines or
trawls are considered to be “fishing vessels”
under the International Rules. Vessels with
trolling lines are not considered fishing ves-
sels. Fishing vessels have the right-of-way re-
gardless of position. Fishing vessels cannot,
however, impede the passage of other ves-
sels in narrow channels.
Sailing vessel right-of-way
Sailing vessels should normally be given the
right-of-way. The exceptions to this are:
1. When the sailing vessel is overtaking the
power-driven vessel, the power-driven
vessel has the right-of-way.
2. Sailing vessels should keep clear of any
fishing vessel.
3. In a narrow channel, a sailing vessel
should not hamper the safe passage of a
power-driven vessel which can navigate
only in such a channel.
Reading buoys and other markers
The waters of the United states are marked
for safe navigation by the lateral system of
buoyage. Simply put, buoys and markers
have an arrangement of shapes, colors, num-
bers and lights to show which side of the buoy
a boater should pass on when navigating in a
particular direction. The markings on these
buoys are oriented from the perspective of be-
ing entered from seaward (the boater is going
towards the port). This means that red buoys
are passed on the starboard (right) side when
proceeding from open water into port, and
black buoys are to port (left) side. When navi-
gating out of port, your position with respect to
the buoys should be reversed; red buoys
should be to port and black buoys to star-
board.
Many bodies of water used by boaters are en-
tirely within the boundaries of a particular
state. The Uniform State Waterway Marking
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							General information
8
System has been devised for these waters.
This system uses buoys and signs with dis-
tinctive shapes and colors to show regulatory
or advisory information. These markers are
white with black letters and orange boarders.
They signify speed zones, restricted areas,
danger areas, and general information.Remember, markings may vary by geograph-
ic location. Always consult local boating au-
thorities before driving your boat in unfamiliar
waters.
ZMU01708
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							General information
9
EMU31490
Fueling instructions
WARNING
EWM01490
GASOLINE AND ITS VAPORS ARE HIGH-
LY FLAMMABLE AND EXPLOSIVE!

Do not smoke when refueling, and keep
away from sparks, flames, or other
sources of ignition.

Stop engine before refueling.

Refuel in a well-ventilated area.

Take care not to spill gasoline. If gaso-
line spills, wipe it up immediately with
dry rags.

Do not overfill the fuel tank.

Tighten the filler cap securely after refu-
eling.

If you should swallow some gasoline, in-
hale a lot of gasoline vapor, or get gaso-
line in your eyes, get immediate medical
attention.

If any gasoline spills onto your skin, im-
mediately wash with soap and water.
Change clothing if gasoline spills on it.

Touch the fuel nozzle to the filler open-
ing or funnel to help prevent electrostat-
ic sparks.
CAUTION:
ECM00010
Use only new clean gasoline which has
been stored in clean containers and is not
contaminated with water or foreign matter.
EMU25570Gasoline
If knocking or pinging occurs, use a different
brand of gasoline or premium unleaded fuel.Gasohol
There are two types of gasohol: gasohol con-
taining ethanol and that containing methanol.
Gasohol containing ethanol can be used if
ethanol content does not exceed 10% and the
fuel meets minimum octane ratings. Yamaha
does not recommended gasohol containing
methanol because it can cause fuel system
damage or engine performance problems.
EMU31440Engine oil
NOTE:
If the recommended engine oil grades are not
available, select an alternative from the fol-
lowing chart according to the average temper-
atures in your area.
Recommended gasoline:
Regular unleaded gasoline with a mini-
mum octane rating of 86 (Pump Oc-
tane Number) = (R+M)/2
Recommended engine oil:
YAMALUBE 4-M FC-W oil or 4-stroke 
motor oil with a combination of the fol-
lowing SAE and API oil classifications
Engine oil type SAE:
10W-30 or 10W-40
Engine oil grade API:
SE, SF, SG, SH, SJ, SL
Engine oil quantity (excluding oil filter):
0.35 L (0.37 US qt) (0.31 Imp.qt)
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							General information
10
CAUTION:
ECM01050
All 4-stroke engines are shipped from the
factory without engine oil.
EMU25742
Propeller selection
The performance of your outboard motor will
be critically affected by your choice of propel-
ler, as an incorrect choice could adversely af-
fect performance and could also seriously
damage the motor. Engine speed depends on
the propeller size and boat load. If engine
speed is too high or too low for good engine
performance, this will have an adverse effect
on the engine.
Yamaha outboard motors are fitted with pro-
pellers chosen to perform well over a range of
applications, but there may be uses where a
propeller with a different pitch would be more
appropriate. For a greater operating load, a
smaller-pitch propeller is more suitable as it
enables the correct engine speed to be main-
tained. Conversely, a larger-pitch propeller is
more suitable for a smaller operating load.
Yamaha dealers stock a range of propellers,
and can advise you and install a propeller on
your outboard that is best suited to your appli-
cation.
NOTE:
Select a propeller which will allow the engine
to reach the middle or upper half of the oper-
ating range at full throttle with the maximum
boat load. If operating conditions such as light
boat loads then allow the engine r/min to rise
above the maximum recommended range, re-
duce the throttle setting to maintain the en-
gine in the proper operating range.
For instructions on propeller removal and in-
stallation, see page 40.
ZMU01710
1. Propeller diameter in inches
2. Propeller pitch in inches
3. Type of propeller (propeller mark)
ZMU04604
- x
123
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							Basic components
11
EMU25797
Main components
NOTE:
* May not be exactly as shown; also may not be included as standard equipment on all models.
EMU25821Fuel tank
If your model included a fuel tank, its parts
and functions are as follows.
1. Top cowling
2. Top cowling lock lever
3. Carrying handle
4. Steering friction screw
5. Anti-cavitation plate
6. Propeller
7. Cooling water inlet
8. Trim rod
9. Clamp bracket
10.Tiller handle
11.Air vent screw
12.Fuel tank cap
13.Manual starter handle
14.Engine stop button/Engine stop lanyard 
switch
15.Clamp screw
16.Rope attachment17.Gear shift lever
18.Choke knob
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							Basic components
12
EMU25850Fuel tank cap
This cap seals the fuel tank. When removed,
the tank can be filled with fuel. To remove the
cap, turn it counterclockwise.
EMU25860Air vent screw
This screw is on the fuel tank cap. To loosen
the screw, turn it counterclockwise.
EMU25872Fuel cock
The fuel cock turns on and off the supply of
fuel from the fuel tank to the engine.
EMU25881Close
To stop fuel flow to the engine, turn the lever
or knob to close position.
Always turn the lever or knob to close position
when the engine is not running.
EMU25891Open
With the lever/knob in this position, fuel flows
to the carburetor.
Normal running is done with the lever/knob in
this position.
EMU25911Tiller handle
To change direction, move the tiller handle to
the left or right as necessary.
1. Fuel tank cap
2. Air vent screw
1. Fuel cock1. Close position
1. Open position
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							Basic components
13
EMU25930Gear shift lever
Pulling the gear shift lever towards you puts
the engine in forward gear so that the boat
moves ahead.
EMU25941Throttle grip
The throttle grip is on the tiller handle. Turn
the grip counterclockwise to increase speed
and clockwise to decrease speed.
EMU25961Throttle indicator
The fuel consumption curve on the throttle in-
dicator shows the relative amount of fuel con-
sumed for each throttle position. Choose the
setting that offers the best performance and
fuel economy for the desired operation.
EMU25971Throttle friction adjuster
A friction device provides adjustable resis-
tance to movement of the throttle grip or the
remote control lever, and can be set accord-
ing to operator preference.
To increase resistance, turn the adjuster
clockwise. To decrease resistance, turn the
adjuster counterclockwise.
WARNING
EWM00031
Do not overtighten the friction adjuster. If
there is too much resistance, it could be
difficult to move the remote control lever
or throttle grip, which could result in an
accident.
When constant speed is desired, tighten the
adjuster to maintain the desired throttle set-
ting.
1. Forward “”
2. Neutral “”
1. Throttle indicator
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							Basic components
14
EMU25990Engine stop lanyard switch
The lock plate must be attached to the engine
stop switch for the engine to run. The lanyard
should be attached to a secure place on the
operator’s clothing, or arm or leg. Should the
operator fall overboard or leave the helm, the
lanyard will pull out the lock plate, stopping ig-
nition to the engine. This will prevent the boat
from running away under power.
WARNING
EWM00120

Attach the engine stop switch lanyard to
a secure place on your clothing, or your
arm or leg while operating.

Do not attach the lanyard to clothing
that could tear loose. Do not route the
lanyard where it could become entan-
gled, preventing it from functioning.

Avoid accidentally pulling the lanyard
during normal operation. Loss of engine
power means the loss of most steering
control. Also, without engine power, the
boat could slow rapidly. This could
cause people and objects in the boat to
be thrown forward.
NOTE:
The engine cannot be started with the lock
plate removed.
EMU26001Engine stop button
To open the ignition circuit and stop the en-
gine, push this button.
EMU26011Choke knob for pull type
To supply the engine with the rich fuel mixture
required to start, pull out this knob.
EMU26070Manual starter handle
To start the engine, first gently pull the handle
out until resistance is felt. From that position,
then pull the handle straight out quickly to
crank the engine.
1. Lock plate
2. Lanyard
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							Basic components
15
EMU26122Steering friction adjuster
A friction device provides adjustable resis-
tance to the steering mechanism, and can be
set according to operator preference. An ad-
justing screw or bolt is located on the swivel
bracket.
To increase resistance, turn the adjuster
clockwise.
To decrease resistance, turn the adjuster
counterclockwise.
WARNING
EWM00040
Do not overtighten the friction adjuster. If
there is too much resistance, it could be
difficult to steer, which could result in an
accident.
EMU26261Trim rod (tilt pin)
The position of the trim rod determines the
minimum trim angle of the outboard motor in
relation to the transom.
EMU30200Tilt support lever for manual tilt model
To keep the outboard motor in the tilted up po-
sition, lock the tilt support lever to the clamp
bracket.
EMU26382Top cowling lock lever (pull up type)
To remove the engine top cowling, pull up the
lock lever(s) and lift off the cowling. When in-
stalling the cowling, check to be sure it fits
properly in the rubber seal. Then lock the
cowling by moving the lever(s) downward.
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