Yamaha 115 C Service Manual

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2-20
EMD60010
TILT SUPPORT LEVER
To keep the outboard motor in the tilted-up
position, lock the tilt support lever to the
clamp bracket.
EMD63210
TOP COWLING LOCK LEVERS
V6
To remove the engine top cowling, pull up
the front and rear lock levers. Then lift off
the cowling. When replacing the cowling,
check to be sure it fits properly in the rubber
seal. Then lock the cowling again by mov-
ing the levers downward.
403033
301021
301022
V6
V6
301023
V4EMD64010
TOP COWLING RELEASE LEVER
V4
The top cowling can be removed by operat-
ing the cowling release lever.
Pulling the front lever unlocks the top cowl-
ing for removal.
When refitting the top cowling:
1) Set the top cowling straight down onto
the engine, being careful to avoid catch-
ing spark plug leads or other wires.
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2-21
2) Align the three cowling hooks with the
locks on the bottom cowling.
3) Press down on the top of the cowling at
the front and both sides of the back until
the three locks click.
4) To make sure the cowling is locked
properly push the cowling from each
side. If it lifts, repeat step 3.
cC
Make sure the cowling lock connection
cable is operating correctly before rein-
stalling the top cowling.
8When the release lever is operated,
both front and rear cowling hooks
should be released at the same time.
If not, adjust the cable adjuster for the
rear clamps.
8Make sure the cable operates smooth-
ly and is free of corrosion.
8Check that the cable is properly
secured in the holder.
8When reinstalling the cowling, insure
that both the front and rear locks have
operated properly.
If the cowling has not been locked prop-
erly some parts may be damaged by the
top cowling shaking during operation.
211013
V4
q
000825
EMU01146
FLUSHING DEVICE
This device 1is used to clean the cooling
water passages of the motor using a gar-
den hose and tap water.
NOTE:
Refer to “Cleaning Cooling-water Pas-
sages” in Chapter 4 for instructions on
usage.
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2-22
EMD80010
WARNING SYSTEM
cC
Do not continue to operate the engine if
the warning device has activated. Con-
sult your Yamaha dealer if the problem
cannot be located and corrected.
EMU01476
OVERHEAT WARNING
This engine has an overheat warning
device. If the engine temperature rises too
high, the warning device will activate.
(1) ; Included  (-); N/A
If the warning system has been activated,
stop the engine and check the water inlet
for clogging.
* Not equipped on all models.
701054
605015
Activation of warning 
device
The engine speed will 
automatically 
decrease to about 
2,000 r/min.
The overheat warning 
indicator will come on.
The buzzer will sound.
Tiller Remote 
control control 
model model
2
2*
1
2
001053
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2-23
EMD84012*
OIL LEVEL WARNING / OIL FILTER
CLOGGING WARNING
This engine has an oil level warning sys-
tem. 
If oil level falls below lower limit, the
warning device will activate.
(2); Included  (—); N/A
If the warning system has been activated,
stop the engine and check for the cause.
NOTE:
The warning for oil filter clogging is simi-
lar to the warnings for low oil level and
overheating.
For easy troubleshooting, it is advisable
to check for engine overheating first, then
oil level and finally oil filter clogging.
1Oil filter
001054
701054
213022
q
905012*
q
Warning device 
activation
The engine speed 
will automatically 
decrease to about 
2,000 r/min.
The oil level warning 
indicator will come on.
The buzzer will sound.
Tiller Remote 
control control 
model model
2
2
2
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EMF00010
Chapter 3
OPERATION
INSTALLATION........................................3-1
Mounting the outboard motor ............3-2
FILLING FUEL AND ENGINE OIL............3-4
Filling fuel ..............................................3-4
Filling oil ................................................3-5
PRE-OPERATION CHECK........................3-9
Operation after a long period of 
storage .................................................3-10
BREAKING IN ENGINE..........................3-11
STARTING ENGINE ..............................3-13
WARMING UP ENGINE.........................3-17
SHIFTING................................................3-18
Forward ...............................................3-18
Reverse ................................................3-18
STOPPING ENGINE...............................3-19
TRIMMING OUTBOARD MOTOR.........3-20
Adjusting trim angle ..........................3-21
TILTING UP/DOWN...............................3-23
CRUISING IN OTHER CONDITIONS.....3-25
Cruising in salt water .........................3-25
Cruising in turbid water .....................3-25
1
2
3
4
5
6
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							3-1
EMF10010
INSTALLATION
cC
Incorrect engine height or obstructions
to smooth water flow (such as the
design or condition of the boat or acce-
ssories such as transom ladders/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
exhaust housing is low enough to prevent
water entry into the powerhead, when water
rises due to waves when the outboard is not
running.
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							3-2
EMU00176
MOUNTING THE OUTBOARD
MOTOR
w
Improper mounting of the outboard
motor could result in hazardous condi-
tions such as poor handling, loss of con-
trol, or fire hazards. Observe the follow-
ing:
8The information presented in this sec-
tion is intended as reference only. It is
not possible to provide complete
instructions for every possible
boat/motor combination. Proper
mounting depends in part on experi-
ence and the specific boat/motor com-
bination.
8Your dealer or other person experi-
enced in proper rigging should mount
the motor. If you are mounting the
motor yourself, you should be trained
by an experienced person. [permanent
mounted type]
8Your dealer or other person experi-
enced in proper outboard motor
mounting should show you how to
mount your motor. [portable type]
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.
1Center line (keel line)
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q104016
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							3-3
w
Overpowering a boat may cause severe
instability. Do not install an outboard
motor with more horsepower than the
maximum rating on the capacity plate of
the boat. If the boat does not have a
capacity plate, consult the boat manufac-
turer.
EMU01299
Mounting Height
To run your boat at optimum efficiency,
the water-resistance (drag) of the boat
and outboard motor must be made as lit-
tle as possible. The mounting-height of
the outboard motor greatly affects the
water-resistance. If the mounting-height
is too high, cavitation tends to occur, thus
reducing the propulsion; and if the pro-
peller tips cut the air, the engine speed
will rise abnormally and cause the engine
to overheat. If the mounting-height is too
low, the water-resistance will increase
and thereby reduce engine efficiency.
Mount the engine so that the anti-cavita-
tion plate is in alignment with the bottom
of the boat .
NOTE:
8The optimum mounting height of the
outboard motor is affected by the
boat/motor combination. Test runs at
different heights can help determine the
optimum mounting height.
8Refer to the section “TRIMMING OUT-
BOARD MOTOR” for instructions on
setting the trim angle of the outboard.
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104014
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							3-4
EMF30010
FILLING FUEL 
AND ENGINE OIL
FILLING FUEL
1) Remove the fuel tank cap.
2) Fill the fuel tank carefully.
3) Close the cap securely after refueling.
Wipe up any spilled fuel.
Ring Free Fuel Additive
Gasoline is a precise blend of many differ-
ent substances, each chosen to give certain
characteristics. Gasoline blends have been
changing in recent years in response to
concerns about pollution and resulting
emissions regulations. One of the most
obvious changes has been the elimination
of lead from most fuels.
As gasoline has changed, the amount of
additives such as aromatics and oxy-
genates has increased. These additives are
important for the engines in passenger cars,
but they can have detrimental effects in
marine engines, particularly 2 cycle out-
boards because of increased deposits in
the combustion chamber. When enough
deposits collect, piston rings begin sticking.
Performance drops and engine wear
increases dramatically.
While many additives available may reduce
deposits, Yamaha recommends the use of
Ring Free Fuel Additive, available from
your Yamaha dealer. Ring Free has repeat-
edly proven its ability to clean combustion
deposits from inside the engine, notably the
critical piston-ring-land area, and fuel sys-
tem components. Follow product labeling
for use instructions
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Fuel tank capacity:
Refer to “SPECIFICATIONS”, Page 4-1.
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							3-5
EMU01800
FILLING OIL
This engine uses the oil injection system,
which provides superior lubrication by
ensuring the proper oil ratio for all operat-
ing conditions. No fuel premixing is need-
ed (except during break-in). Simply pour
gasoline into the fuel tank and oil into the
oil tank. Convenient indicator segments
indicate the status of the oil supply. For
details on reading the indicator segments,
see “Oil level indicator” in this chapter.
To fill the engine oil tank, proceed as fol-
lows:
w
Do not add gasoline into the oil tank. Fire
or explosion could result.
E
Engine oil tank capacity:
See Chapter 4, “Specifications.”
001475
EMU01824
When remote oil tank is used
115–130
1) Pour oil into the remote oil tank.
NOTE:
The oil level lines on the remote oil tank
indicate the amount of additional oil that
can be added to the tank. The top oil level
line indicates approximately 1.9 L (0.5 US
gal, 0.4 Imp gal) can be added, and the
bottom oil level line indicates approxi-
mately 3.8 L (1 US gal, 0.8 Imp gal) can be
added.
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