Yamaha F15 Owners Manual

							 
25 
Operation 
EMU26901 
Installation
CAUTION:
 
ECM00110  
Incorrect engine height or obstructions
to smooth water flow (such as the design
or condition of the boat, or accessories
such as transom ladders or depth finder
transducers) can create airborne water
spray while the boat is cruising. Severe
engine damage may result if the motor is
operated continuously in the presence of 
airborne water spray.
NOTE:
 
During water testing check the buoyancy of
the boat, at rest, with its maximum load.
Check that the static water level on the ex-
haust housing is low enough to prevent wa-
ter entry into the powerhead, when water
rises due to waves when the outboard is not 
running. 
EMU26910 
Mounting the outboard motor
WARNING
 
EWM00820  
 
Overpowering a boat could cause se-
vere instability. Do not install an out-
board motor with more horsepower
than the maximum rating on the capac-
ity plate of the boat. If the boat does not
have a capacity plate, consult the boat
manufacturer. 
 
The information presented in this sec-
tion is intended as reference only. It is
not possible to provide complete in-
structions for every possible boat and
motor combination. Proper mounting
depends in part on experience and the 
specific boat and motor combination.
WARNING
 
EWM00830  
Improper mounting of the outboard mo-
tor could result in hazardous conditions
such as poor handling, loss of control, or
fire hazards. Observe the following: 
 
For permanently mounted models, your
dealer or other person experienced in
proper rigging should mount the motor.
If you are mounting the motor yourself,
you should be trained by an experi-
enced person. 
 
For portable models, your dealer or oth-
er person experienced in proper out-
board motor mounting should show 
you how to mount your motor. 
Mount the outboard motor on the center line
(keel line) of the boat, and ensure that the
boat itself is well balanced. Otherwise the
boat will be hard to steer. For boats without
a keel or which are asymmetrical, consult
your dealer. 
EMU26920 
Mounting height 
To run your boat at optimum efficiency, the
water resistance (drag) of the boat and out-
board motor must be made as little as possi-
ble. The mounting height of the outboard 
1. Center line (keel line)
ZMU017601 
						

							 
Operation 
26 
motor greatly affects the water resistance. If
the mounting height is too high, cavitation
tends to occur, thus reducing the propulsion;
and if the propeller tips cut the air, the engine
speed will rise abnormally and cause the en-
gine to overheat. If the mounting height is too
low, the water resistance will increase and
thereby reduce engine efficiency. Mount the
outboard motor so that the anti-cavitation
plate is between the bottom of the boat and
a level 25 mm (1 in.) below it.
NOTE:
 
 
The optimum mounting height of the out-
board motor is affected by the boat and
motor combination and the desired use.
Test runs at different heights can help de-
termine the optimum mounting height.
Consult your Yamaha dealer or boat man-
ufacturer for further information on deter-
mining the proper mounting height. 
 
For instructions on setting the trim angle of 
the outboard motor, see page 38. 
EMU26970 
Clamping the outboard motor 
1. Place the outboard motor on the tran-
som so that it is positioned as close to
the center as possible. Tighten the tran-
som clamp screws evenly and securely.
Occasionally check the clamp screws
for tightness during operation of the out-
board motor because they could be-come loose due to engine vibration.
WARNING
 
EWM00640  
Loose clamp screws could allow the out-
board motor to fall off or move on the
transom. This could cause loss of control
and serious injury. Make sure the tran-
som screws are tightened securely. Oc-
casionally check the screws for tightness 
during operation. 
2. If the engine restraint cable attachment
is equipped on your engine, an engine
restraint cable or chain should be used.
Attach one end to the engine restraint
cable attachment and the other to a se-
cure mounting point on the boat. Other-
wise the engine could be completely lost
if it accidentally falls off the transom.
3. Secure the clamp bracket to the transom
using the bolts provided with the out-
ZMU02011
0–25mm
(0–1in.)ZMU02012
ZMU02013 
						

							 
Operation 
27 
board (if packed). For details, consult
your Yamaha dealer.
WARNING
 
EWM00650  
Avoid using bolts, nuts or washers other
than those contained in the engine pack-
aging. If used, they must be of at least the
same quality of material and strength and
must be tightened securely. After tighten-
ing, test run the engine and check their 
tightness. 
EMU30172 
Breaking in engine 
Your new engine requires a period of break-
in to allow mating surfaces of moving parts to
wear in evenly. Correct break-in will help en-
sure proper performance and longer engine
life.
CAUTION:
 
ECM00800  
Failure to follow the break-in procedure
could result in reduced engine life or 
even severe engine damage. 
EMU27080 
Procedure for 4-stroke models 
Run the engine under load (in gear with a
propeller installed) as follows.
1. For the first hour of operation:Run the engine at 2000 r/min or at ap-
proximately half throttle.
2. For the second hour of operation:
Run the engine at 3000 r/min or at ap-
proximately three-quarter throttle.
3. For the next eight hours of operation:
Avoid continuous operation at full throt-
tle for more than five minutes at a time.
4. After the first 10 hours:
Operate the engine normally. 
EMU27101 
Preoperation checks
WARNING
 
EWM00080  
If any item in the preoperation check is
not working properly, have it inspected
and repaired before operating the out-
board motor. Otherwise an accident 
could occur.
CAUTION:
 
ECM00120  
Do not start the engine out of water. Over-
heating and serious engine damage can 
occur. 
EMU27110 
Fuel 
 
Check to be sure you have plenty of fuel
for your trip. 
 
Make sure there are no fuel leaks or gaso-
line fumes. 
 
Check fuel line connections to be sure they
are tight (if equipped Yamaha fuel tank or
boat tank). 
 
Be sure the fuel tank is positioned on a se-
cure, flat surface, and that the fuel line is
not twisted or flattened, or likely to contact
sharp objects (if equipped Yamaha fuel
tank or boat tank). 
EMU27130 
Controls 
 
Check throttle, shift, and steering for prop- 
1. Bolts
ZMU02631
1 
						

							 
Operation 
28 
er operation before starting the engine. 
 
The controls should work smoothly, with-
out binding or unusual free play. 
 
Look for loose or damaged connections. 
 
Check operation of the starter and stop
switches when the outboard motor is in the
water. 
EMU27140 
Engine 
 
Check the engine and engine mounting. 
 
Look for loose or damaged fasteners. 
 
Check the propeller for damage. 
EMU27163 
Checking the engine oil level 
1. Put the outboard motor in an upright po-
sition (not tilted).
2. Remove oil dipstick and wipe it clean.
3. Completely insert the dipstick and re-
move it again.
4. Check the oil level using the dipstick to
be sure the level falls between the upper
and lower marks. Fill with oil if it is below
the lower mark, or drain to the specified
level if it is above the upper mark.
NOTE:
 
Be sure to completely insert the dipstick into 
the dipstick guide. 
EMU30021 
Filling fuel
WARNING
 
EWM00060  
Gasoline and its vapors are highly flam-
mable and explosive. Keep away from
sparks, cigarettes, flames, or other 
sources of ignition. 
1. Remove the fuel tank cap.
2. Carefully fill the fuel tank.
3. Securely close the cap after filling the
tank. Wipe up any spilled fuel. 
EMU27270 
Ring Free Fuel Additive 
Gasoline is a precise blend of many different
substances, each chosen to give certain
characteristics. Gasoline blends have been
changing in recent years in response to con-
cerns about pollution and resulting emis-
sions regulations. One of the most obvious
changes has been the elimination of lead
from most fuels.
As gasoline has changed, the amount of ad-
ditives such as aromatics and oxygenates
has increased. These additives are impor-
tant for the engines in passenger cars, but
they can have detrimental effects in marine
engines, because of increased deposits in
the combustion chamber. When enough de-
posits collect, piston rings begin sticking.
Performance drops and engine wear in-
creases dramatically.
While many additives available may reduce
deposits, Yamaha recommends the use of 
Ring Free Fuel Additive 
, available from
your Yamaha dealer.  
Ring Free Fuel Addi-
tive 
 has repeatedly proven its ability to clean
combustion deposits from inside the engine,
notably the critical piston-ring-land area, and
fuel system components. Follow product la-
beling for use instructions. 
1. Lower level mark
2. Oil dipstick
3. Upper level mark
ZMU02082
1
3
2 
						

							 
Operation 
29 
EMU27450 
Operating engine 
EMU27461 
Feeding fuel (portable tank)
WARNING
 
EWM00420  
 
Before starting the engine, make sure
that the boat is tightly moored and that
you can steer clear of any obstructions.
Be sure there are no swimmers in the
water near you. 
 
When the air vent screw is loosened,
gasoline vapor will be released. Gaso-
line is highly flammable, and its vapors
are flammable and explosive. Refrain
from smoking, and keep away from
open flames and sparks while loosen-
ing the air vent screw. 
 
This product emits exhaust gases
which contain carbon monoxide, a col-
orless, odorless gas which could cause
brain damage or death when inhaled.
Symptoms include nausea, dizziness,
and drowsiness. Keep cockpit and cab-
in areas well ventilated. Avoid blocking 
exhaust outlets. 
1. If there is an air vent screw on the fuel
tank cap, loosen it 2 or 3 turns.
2. If there is a fuel joint on the motor, firmly
connect the fuel line to the joint. Then
firmly connect the other end of the fuelline to the joint on the fuel tank.
3. If a steering friction adjuster is provided
on your outboard motor, securely attach
the fuel line to the fuel line clamp.
NOTE:
 
During engine operation place the tank hori-
zontally, otherwise fuel cannot be drawn 
from the fuel tank.
4. Squeeze the primer pump with the outlet
end up until you feel it become firm.
ZMU02022
ZMU02024
ZMU02023
ZMU02025 
						

							 
Operation 
30 
EMU27490 
Starting engine 
EMU27505 
Manual start models (tiller control) 
1. Place the gear shift lever in neutral.
NOTE:
 
The start-in-gear protection device prevents
the engine from starting except when in neu- 
tral.
2. Attach the engine stop switch lanyard to
a secure place on your clothing, or your
arm or leg. Then install the lock plate on
the other end of the lanyard into the en-
gine stop switch.
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 thelanyard where it could become entan-
gled, preventing it from functioning. 
 
Avoid accidentally pulling the lanyard
during normal operation. Loss of en-
gine 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. 
3. Place the throttle grip in the “”
(start) position.
4. Pull out / turn the choke knob fully. After
the engine starts, replace / return the
knob to the home position.
ZMU01988
N
N
ZMU04881
ZMU02026
ZMU02027 
						

							 
Operation 
31
NOTE:
 
 
It is not necessary to use the choke when
starting a warm engine. 
 
If the choke knob is left in the “”
(start) position while the engine is running, 
the engine will run poorly or stall.
5. Pull the manual starter handle slowly un-
til you feel resistance. Then give a
strong pull straight out to crank and start
the engine. Repeat if necessary.
6. After the engine starts, slowly return the
manual starter handle to its original po-
sition before releasing it.
7. Slowly return the throttle grip to the fully
closed position.
NOTE:
 
 
When the engine is cold, it needs to be
warmed up. For further information, see
page 35. 
 
If the engine does not start on the first try,
repeat the procedure. If the engine fails to
start after 4 or 5 tries, open the throttle a
small amount (between 1/8 and 1/4) and
try again. Also if the engine is warm and
fails to start, open the throttle a same
amount and try to start the engine again. If 
the engine still fails to start, see page 74. 
EMU27562 
Electric start models 
1. Place the gear shift lever in neutral.
ZMU02355
ZMU02029
ZMU02030
ZMU01988
N 
						

							 
Operation 
32
NOTE:
 
The start-in-gear protection device prevents
the engine from starting except when in neu- 
tral.
2. Attach the engine stop switch lanyard to
a secure place on your clothing, or your
arm or leg. Then install the lock plate on
the other end of the lanyard into the en-
gine stop switch.
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 en-
gine 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. 
3. Place the throttle grip in the “”
(start) position. After the engine starts,
return the throttle to the fully closed po-
sition.
4. Pull out / turn the choke knob fully. After
the engine starts, replace / return the
knob to the home position.
NOTE:
 
 
It is not necessary to use the choke when
starting a warm engine.
N
ZMU04881ZMU02026
ZMU02027
ZMU02355 
						

							 
Operation 
33 
 
If the choke knob is left in the “”
(start) position while the engine is running, 
the engine will run poorly or stall.
5. Push the starter button to start the mo-
tor. (Repeat if necessary.)
6. Immediately after the engine starts, re-
lease the starter button to allow it to re-
turn to its original position.
7. Slowly return the throttle grip to the fully
closed position so that the engine does
not stall.
CAUTION:
 
ECM00160  
 
Never push the starter button while the
engine is running. 
 
Do not keep the starter motor turning
for more than 5 seconds. If the starter
motor is turned continuously for more
than 5 seconds, the battery will be
quickly discharged, thus making it im-
possible to start the engine. The starter
can also be damaged. If the engine will
not start after 5 seconds of cranking,
release the starter button, wait 10 sec- 
onds, then crank the engine again.
NOTE:
 
 
When the engine is cold, it needs to be
warmed up. For further information, see
page 35. 
 
If the engine does not start on the first try,repeat the procedure. If the engine fails to
start after 4 or 5 tries, open the throttle a
small amount (between 1/8 and 1/4) and
try again. Also if the engine is warm and
fails to start, open the throttle a same
amount and try to start the engine again. If 
the engine still fails to start, see page 74. 
EMU27642 
Electric start / remote control models 
1. Place the remote control lever in neutral.
NOTE:
 
The start-in-gear protection device prevents
the engine from starting except when in neu- 
tral.
2. Attach the engine stop switch lanyard to
a secure place on your clothing, or your
arm or leg. Then install the lock plate on
the other end of the lanyard into the en-
gine stop switch.
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 en-
ZMU04880 
						

							 
Operation 
34 
gine 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. 
3. Turn the main switch to “” (on).
4. Open the throttle slightly without shifting
using the neutral throttle lever or free ac-
celerator. You may need to change the
throttle opening slightly depending on
engine temperature. After the engine
starts, return the throttle to the original
position.
NOTE:
 
 
On remote controls equipped with a neu-
tral throttle lever, a good starting point is to
lift the lever just until you feel resistance,
then lift slightly more. 
 
The neutral throttle lever or free accelera-
tor can only be used when the remote con- 
trol lever is in neutral.
5. Press in and hold the main switch to op-
erate the remote choke system. The re-
mote choke switch automatically returns
to its normal position when you release
your hand. Therefore keep the switch
pressed in.
NOTE:
 
 
It is not necessary to use the choke when
starting a warm engine. 
 
Push in the main switch fully, or the remote 
choke system will not operate.
OFF
ON
ZMU01880
N
ZMU02314
START OFFON
ZMU02315