Yamaha F115 Owners Manual

							 
Maintenance 
65 
When fitting the plug, always clean the gas-
ket surface and use a new gasket. Wipe off
any dirt from the threads and screw in the
spark plug to the correct torque.
NOTE:
 
If a torque-wrench is not available when you
are fitting a spark plug, a good estimate of
the correct torque is 1/4 to 1/2 a turn past fin-
ger-tight. Have the spark plug adjusted to the
correct torque as soon as possible with a 
torque-wrench. 
EMU28962 
Checking fuel system
WARNING
 
EWM00060  
Gasoline and its vapors are highly flam-
mable and explosive. Keep away from
sparks, cigarettes, flames, or other 
sources of ignition.
WARNING
 
EWM00910  
Leaking fuel can result in fire or explo-
sion. 
 
Check for fuel leakage regularly. 
 
If any fuel leakage is found, the fuel
system must be repaired by a qualified
mechanic. Improper repairs can make 
the outboard unsafe to operate. 
Check the fuel lines for leaks, crack, or mal-
function. If a problem is found, your Yamaha
dealer or other qualified mechanic should re-
pair it immediately.
Checkpoints 
 
Fuel system parts leakage 
 
Fuel line joint leakage 
 
Fuel line cracks or other damage 
 
Fuel connector leakage 
1. Spark plug gap
2. Spark plug I.D. mark (NGK)
3. Spark plug part number 
Spark plug gap:
1.0–1.1 mm (0.039–0.043 in)
Spark plug torque:
25.0 Nm (18.4 ft-lb) (2.55 kgf-m)
ZMU04267 
						

							 
Maintenance 
66 
EMU29041 
Inspecting idling speed
WARNING
 
EWM00451  
 
Do not touch or remove electrical parts
when starting or during operation. 
 
Keep hands, hair, and clothes away
from the flywheel and other rotating 
parts while the engine is running.
CAUTION:
 
ECM00490  
This procedure must be performed while
the outboard motor is in the water. A
flushing attachment or test tank can be 
used. 
A diagnostic tachometer should be used for
this procedure. Results may vary depending
on whether testing is conducted with the
flushing attachment, in a test tank, or with the
outboard motor in the water.
1. Start the engine and allow it to warm up
fully in neutral until it is running smooth-
ly.
NOTE:
 
Correct idling speed inspection is only possi-
ble if the engine is fully warmed up. If not
warmed up fully, the idle speed will measure
higher than normal. If you have difficulty ver-
ifying the idle speed, or the idle speed re-
quires adjustment, consult a Yamaha dealer 
or other qualified mechanic.
2. Verify whether the idle speed is set to
specification. For idle speed specifica-
tions, see page 56. 
EMU29073 
Changing engine oil
WARNING
 
EWM00760  
 
Avoid draining the engine oil immedi-
ately after stopping the engine. The oilis hot and should be handled with care
to avoid burns. 
 
Be sure the outboard motor is securely
fastened to the transom or a stable 
stand.
CAUTION:
 
ECM00970  
 
Do not overfill the oil, and be sure the
outboard motor is upright (not tilted)
when checking and changing the en-
gine oil. 
 
If the oil level is above the upper level
mark, drain until the level meets the
specified capacity. Overfilling the oil 
could cause leakage or damage.
CAUTION:
 
ECM01240  
Change the engine oil after the first 10
hours of operation, and every 100 hours
or at 6-month intervals thereafter. Other- 
wise the engine will wear quickly.
NOTE:
 
Change the engine oil when the oil is still 
warm.
1. Put the outboard motor in an upright po-
sition (not tilted).
2. Prepare a suitable container that holds a
larger amount than the engine oil capac-
ity. Loosen and remove the drain screw
ZMU04270 
						

							 
Maintenance 
67 
while holding the container under the
drain hole. Then remove the oil filler cap.
Let the oil drain completely. Wipe up any
spilled oil immediately.
3. Put a new gasket on the oil drain screw.
Apply a light coat of oil to the gasket and
install the drain screw.
NOTE:
 
If a torque wrench is not available when you
are installing the drain screw, finger tighten
the screw just until the gasket comes into
contact with the surface of the drain hole.
Then tighten 1/4 to 1/2 turn more. Tighten
the drain screw to the correct torque with a 
torque wrench as soon as possible.
4. Add the correct amount of oil through the
filler hole. Install the filler cap.5. Start the engine and watch to make sure
the low oil pressure warning indicator (if
equipped) turns off. Make sure that
there are no oil leaks.
CAUTION:
 
ECM00680  
If the low oil pressure warning indicator
does not turn off or if there are oil leaks,
stop the engine and find the cause. Con-
tinued operation with a problem could
cause severe engine damage. Consult
your Yamaha dealer if the problem can- 
not be located and corrected. 
6. Turn off the engine and wait 3 minutes.
Recheck the oil level using the dipstick
to be sure the level falls between the up-
per 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. 
1. Drain screw 
Drain screw tightening torque:
28.0 Nm (20.7 ft-lb) (2.86 kgf-m)
Recommended engine oil:
4-stroke outboard motor oil
Engine oil quantity (excluding oil filter):
4.3 L (4.55 US qt) (3.78 Imp.qt)
1
ZMU04241
 
1. Oil filler cap
1
ZMU04271 
						

							 
Maintenance 
68 
7. Dispose of used oil according to local
regulations.
NOTE:
 
 
For more information on the disposal of
used oil, consult your Yamaha dealer. 
 
Change the oil more often when operating
the engine under adverse conditions such 
as extended trolling. 
EMU29112 
Checking wiring and connectors 
 
Check that each grounding wire is properly
secured. 
 
Check that each connector is engaged se-
curely. 
EMU29120 
Exhaust leakage 
Start the engine and check that no exhaust
leaks from the joints between the exhaust
cover, cylinder head, and body cylinder. 
EMU29130 
Water leakage 
Start the engine and check that no water
leaks from the joints between the exhaust
cover, cylinder head, and body cylinder. 
EMU29140 
Engine oil leakage 
Check for oil leaks on the around the engine.
NOTE:
 
If any leaks are found, consult your Yamaha 
dealer. 
EMU29153 
Checking power trim and tilt system
WARNING
 
EWM00430  
 
Never get under the lower unit while it
is tilted, even when the tilt support lever
is locked. Severe injury could occur if
the outboard motor accidentally falls. 
 
Make sure no one is under the outboard 
motor before performing this test. 
1. Check the power trim and tilt unit for any
sign of oil leaks.
2. Operate each of the power trim and tilt
switches on the remote control and en-
gine bottom cowling (if equipped) to
check that all switches work.
3. Tilt the outboard motor up and check
that the tilt rod and trim rods are extend-
ed completely.
ZMU02058
ZMU04286
 
1. Tilt rod
ZMU02633
1
23 
						

							 
Maintenance 
69 
4. Use the tilt support lever to lock the mo-
tor in the up position. Operate the tilt
down switch briefly so the motor is sup-
ported by the tilt support lever.
5. Check that the tilt rod and trim rods are
free of corrosion or other flaws.
6. Activate the tilt-down switch until the trim
rods have retracted completely into the
cylinders.
7. Activate the trim-up switch until the tilt
rod is fully extended. Unlock the tilt sup-
port lever.
8. Tilt the outboard motor down. Check
that the tilt rod and trim rods operate
smoothly.
NOTE:
 
Consult your Yamaha dealer if any operation 
is abnormal. 
EMU29171 
Checking propeller
WARNING
 
EWM00321  
You could be seriously injured if the en-
gine accidentally starts when you are
near the propeller. 
 
Before inspecting, removing, or install-
ing the propeller, remove the spark
plug caps from the spark plugs. Also,
place the shift control in neutral, turn
the main switch to “” (off) and re-
move the key, and remove the lanyard
from the engine stop switch. Turn off
the battery cut-off switch if your boat
has one. 
 
Do not use your hand to hold the pro-
peller when loosening or tightening the
propeller nut. Put a wood block be-
tween the anti-cavitation plate and the
propeller to prevent the propeller from 
turning. 
2. Trim rods
3. Tilt support lever
1. Tilt support lever
ZMU02634
1
ZMU02635
ZMU04262 
						

							 
Maintenance 
70 
Checkpoints 
 
Check each of the propeller blades for
wear, erosion from cavitation or ventila-
tion, or other damage. 
 
Check the propeller shaft for damage. 
 
Check the splines / shear pin for wear or
damage. 
 
Check for fish line tangled around the pro-
peller shaft. 
 
Check the propeller shaft oil seal for dam-
age.
NOTE:
 
If the shear pin equipped: it is designed to
break if the propeller hits a hard underwater
obstacle to help protect the propeller and
drive mechanism. The propeller will then
spin freely on the shaft. If this happens, the 
shear pin must be replaced. 
EMU30660 
Removing the propeller 
EMU29194 
Spline models 
1. Straighten the cotter pin and pull it out
using a pair of pliers.
2. Remove the propeller nut, washer, and
spacer (if equipped).
3. Remove the propeller and thrust wash-
er. 
EMU30670 
Installing the Propeller 
EMU29242 
Spline models
WARNING
 
EWM00770  
On counter rotation models, be sure to
use a propeller intended for counter-
clockwise rotation. These propellers are
identified with the letter “L” after the size
indication on the propeller. Otherwise the
boat could move in the opposite direction
ZMU01897
 
1. Cotter pin
2. Propeller nut
3. Washer
4. Spacer
5. Propeller
6. Thrust washer 
						

							 
Maintenance 
71 
from that expected.
CAUTION:
 
ECM00340  
 
Be sure to install the thrust washer be-
fore installing the propeller, otherwise
the lower case and propeller boss
could be damaged. 
 
Be sure to use a new cotter pin and
bend the ends over securely. Otherwise
the propeller could come off during op- 
eration and be lost. 
1. Apply Yamaha marine grease or a cor-
rosion resistant grease to the propeller
shaft.
2. Install the thrust washer and propeller
on the propeller shaft.
3. Install the spacer and washer. Tighten
the propeller nut to the specified torque.
4. Align the propeller nut with the propeller
shaft hole. Insert a new cotter pin in the
hole and bend the cotter pin ends.
NOTE:
 
If the propeller nut does not align with the
propeller shaft hole after tightening to the
specified torque, tighten the nut further to 
align it with the hole. 
EMU29282 
Changing gear oil
WARNING
 
EWM00800  
 
Be sure the outboard motor is securely
fastened to the transom or a stable
stand. You could be severely injured if
the outboard motor falls on you. 
 
Never get under the lower unit while it
is tilted, even when the tilt support lever
or knob is locked. Severe injury could
occur if the outboard motor accidental- 
ly falls. 
1. Tilt the outboard motor so that the gear
oil drain screw is at the lowest point pos-
sible.
2. Place a suitable container under the
gear case.
3. Remove the gear oil drain screw and
gasket.
NOTE:
 
 
If a magnetic gear oil drain screw is
equipped, remove all metal particles from
the screw before installing it. 
 
Always use new gaskets. Do not reuse the 
removed gaskets.
4. Remove the oil level plug and gasket to Propeller nut tightening torque:
55.0 Nm (40.6 ft-lb) (5.61 kgf-m) 
1. Gear oil drain screw
2. Oil level plug
ZMU03273
2
1 
						

							 
Maintenance 
72 
allow the oil to drain completely.
CAUTION:
 
ECM00710  
Inspect the used oil after it has been
drained. If the oil is milky, water is getting
into the gear case which can cause gear
damage. Consult a Yamaha dealer for re- 
pair of the lower unit seals.
NOTE:
 
For disposal of used oil, consult your 
Yamaha dealer.
5. With the outboard motor in a vertical po-
sition, and using a flexible or pressur-
ized filling device, inject the gear oil into
the gear oil drain screw hole.
6. Put a new gasket on the oil level plug.
When the oil begins to flow out of the oil
level plug hole, insert and tighten the oil
level plug.
7. Put a new gasket on the gear oil drain
screw. Insert and tighten the gear oildrain screw. 
EMU29312 
Inspecting and replacing anode(s) 
Yamaha outboard motors are protected from
corrosion by sacrificial anodes. Inspect the
external anodes periodically. Remove scales
from the surfaces of the anodes. Consult a
Yamaha dealer for replacement of external
anodes.
CAUTION:
 
ECM00720  
Do not paint anodes, as this would render 
them ineffective.
NOTE:
 
Inspect ground leads attached to external
anodes on equipped models. Consult a
Yamaha dealer for inspection and replace-
ment of internal anodes attached to the pow- 
er unit. Recommended gear oil:
Hypoid gear oil SAE#90
Gear oil quantity:
F115TR 760.0 cm 
3
 
 (25.70 US oz) 
(26.81 Imp.oz)
LF115TR 715.0 cm 
3
 
 (24.17 US oz) 
(25.22 Imp.oz)
ZMU03274
ZMU01901
ZMU04008 
						

							 
Maintenance 
73 
EMU29320 
Checking battery (for electric start 
models)
WARNING
 
EWM00330  
Battery electrolytic fluid is dangerous; it
contains sulfuric acid and therefore is
poisonous and highly caustic.
Always follow these preventive mea-
sures: 
 
Avoid bodily contact with electrolytic
fluid as it can cause severe burns or
permanent eye injury. 
 
Wear protective eye gear when han-
dling or working near batteries.
Antidote (EXTERNAL): 
 
SKIN - Flush with water. 
 
EYES - Flush with water for 15 minutes
and get immediate medical attention.
Antidote (INTERNAL): 
 
Drink large quantities of water or milk
followed by milk of magnesia, beaten
egg, or vegetable oil. Get immediate
medical attention.
Batteries also generate explosive hydro-
gen gas; therefore, you should always
follow these preventive measures: 
 
Charge batteries in a well-ventilated ar-
ea. 
 
Keep batteries away from fire, sparks,
or open flames (for example: welding
equipment, lighted cigarettes, and so
on.) 
 
DO NOT SMOKE when charging or han-
dling batteries.
KEEP BATTERIES AND ELECTROLYTIC 
FLUID OUT OF REACH OF CHILDREN.
CAUTION:
 
ECM00360  
 
A poorly maintained battery will quicklydeteriorate. 
 
Ordinary tap water contains minerals
harmful to a battery, and should not be 
used for topping up. 
1. Check the electrolyte level at least once
a month. Fill to the manufacturer’s rec-
ommended level when necessary. Top
up only with distilled water (or pure de-
ionized water suitable to use in batter-
ies).
2. Always keep the battery in a good state
of charge. Installing a voltmeter will help
you monitor your battery. If you will not
use the boat for a month or more, re-
move the battery from the boat and store
it in a cool, dark place. Completely re-
charge the battery before using it.
3. If the battery will be stored for longer
than a month, check the specific gravity
of the fluid at least once a month and re-
charge the battery when it is low.
NOTE:
 
Consult a Yamaha dealer when charging or 
re-charging batteries. 
EMU29331 
Connecting the battery
WARNING
 
EWM00570  
Mount the battery holder securely in a
dry, well-ventilated, vibration-free loca- 
						

							 
Maintenance 
74 
tion in the boat. Install a fully charged bat- 
tery in the holder.
CAUTION:
 
ECM01121  
 
Make sure the main switch (on applica-
ble models) is “” (off) before work-
ing on the battery. 
 
Reversal of the battery cables will dam-
age the electrical parts. 
 
Connect the red battery cable first
when installing the battery and discon-
nect the black battery cable first when
removing it. Otherwise, the electrical
parts can be damaged. 
 
The electrical contacts of the battery
and cables must be clean and properly
connected, or the battery will not start 
the engine. 
Connect the red battery cable to the POSI-
TIVE (+) terminal first. Then connect the
black battery cable to the NEGATIVE (-) ter-
minal. 
EMU29370 
Disconnecting the battery 
Disconnect the BLACK cable from the NEG-
ATIVE (-) terminal first. Then disconnect the
RED cable from the POSITIVE (+) terminal. 
EMU29390 
Checking top cowling 
Check the fitting of the top cowling by push-
ing it with both hands. If it is loose have it re-
paired by your Yamaha dealer. 
EMU29400 
Coating the boat bottom 
A clean hull improves boat performance. The
boat bottom should be kept as clean of ma-
rine growth as possible. If necessary, the
boat bottom can be coated with an anti-foul-
ing paint approved for your area to inhibit
marine growth.
Do not use anti-fouling paint which includes
copper or graphite. These paints can cause
more rapid engine corrosion. 
1. Red cable
2. Black cable
3. Battery
ZMU04246