
Instrument and control functions
3-16
3
EAU13076
Fuel tank cap
To open the fuel tank cap
Open the fuel tank cap lock cover, in-
sert the key into the lock, and then turn
it 1/4 turn clockwise. The lock will be
released and the fuel tank cap can be
opened.
To close the fuel tank cap
With the key still inserted in the lock,
push down the fuel tank cap. Turn the
key 1/4 turn counterclockwise, remove
it, and then close the lock cover.
TIP
The fuel tank cap cannot be closed un-
less the key is in the lock. In addition,
the key cannot be removed if the cap is
not properly closed and locked.
WARNING
EWA11092
Make sure that the fuel tank cap is
properly closed after filling fuel.
Leaking fuel is a fire hazard.
EAU13213
Fuel
Make sure there is sufficient gasoline in
the tank.
WARNING
EWA10882
Gasoline and gasoline vapors are
extremely flammable. To avoid fires
and explosions and to reduce the
risk of injury when refueling, follow
these instructions.
1. Before refueling, turn off the en-
gine and be sure that no one is sit-
ting on the vehicle. Never refuel
while smoking, or while in the vi-
cinity of sparks, open flames, or
other sources of ignition such as
the pilot lights of water heaters
and clothes dryers.
2. Do not overfill the fuel tank. Stop
filling when the fuel reaches the
bottom of the filler tube. Because
fuel expands when it heats up,
heat from the engine or the sun
can cause fuel to spill out of the
fuel tank.
3. Wipe up any spilled fuel immedi-
ately. NOTICE: Immediately
wipe off spilled fuel with a clean,1. Fuel tank cap lock cover
2. Unlock.
ZAUM1591
2
1
1. Fuel tank filler tube
2. Maximum fuel level
UB5GE0E0.book Page 16 Thursday, August 23, 2018 10:05 AM
![YAMAHA YZF-R125 2019 Owners Manual Instrument and control functions
3-17
3 dry, soft cloth, since fuel may
deteriorate painted surfaces or
plastic parts.
[ECA10072]
4. Be sure to securely close the fuel
tank cap.
WARNING
EWA15152
Gaso YAMAHA YZF-R125 2019 Owners Manual Instrument and control functions
3-17
3 dry, soft cloth, since fuel may
deteriorate painted surfaces or
plastic parts.
[ECA10072]
4. Be sure to securely close the fuel
tank cap.
WARNING
EWA15152
Gaso](/manual-img/51/54241/w960_54241-30.png)
Instrument and control functions
3-17
3 dry, soft cloth, since fuel may
deteriorate painted surfaces or
plastic parts.
[ECA10072]
4. Be sure to securely close the fuel
tank cap.
WARNING
EWA15152
Gasoline is poisonous and can
cause injury or death. Handle gaso-
line with care. Never siphon gasoline
by mouth. If you should swallow
some gasoline or inhale a lot of gas-
oline vapor, or get some gasoline in
your eyes, see your doctor immedi-
ately. If gasoline spills on your skin,
wash with soap and water. If gaso-
line spills on your clothing, change
your clothes.
EAU75320
NOTICE
ECA11401
Use only unleaded gasoline. The use
of leaded gasoline will cause severe
damage to internal engine parts,
such as the valves and piston rings,
as well as to the exhaust system.
TIP
This mark identifies the recom-
mended fuel for this vehicle as
specified by European regulation
(EN228).
Check that gasoline nozzle has
the same identifier when fueling.
Your Yamaha engine has been de-
signed to use premium unleaded gas-
oline with a research octane number of
95 or higher. If knocking (or pinging)
occurs, use a gasoline of a different
brand. Use of unleaded fuel will extend
spark plug life and reduce mainte-
nance costs.
Gasohol
There are two types of gasohol: gaso-
hol containing ethanol and that con-
taining methanol. Gasohol containing
ethanol can be used if the ethanol con-
tent does not exceed 10% (E10). Gas-
ohol containing methanol is not
recommended by Yamaha because it
can cause damage to the fuel system
or vehicle performance problems.
Recommended fuel:
Premium unleaded gasoline (Gaso-
hol [E10] acceptable)
Fuel tank capacity:
11 L (2.9 US gal, 2.4 Imp.gal)
Fuel reserve amount (when the fuel
level warning light comes on):
3.0 L (0.79 US gal, 0.66 Imp.gal)
E5E10
UB5GE0E0.book Page 17 Thursday, August 23, 2018 10:05 AM

Operation and important riding points
5-2
5
EAUM4021
Starting the engine
Under normal conditions, shift the
transmission into neutral before start-
ing the engine. To start the engine with
the transmission in gear, the sidestand
must be up and the clutch lever pulled.
To start the engine
1. Set the engine stop switch to the
run position, and turn the main
switch to the on position.
2. Confirm the following lights come
on for a few seconds and then go
off.
Engine trouble warning light
Coolant warning light
Shift timing indicator light
TIP
The ABS warning light should go
off after reaching a speed of 10
km/h (6 mi/h) or higher.
The neutral position indicator light
should be on when the transmis-
sion is in neutral.
NOTICE
ECA24110
If a warning or indicator light does
not work as described above, have a
Yamaha dealer check the vehicle.
3. Shift the transmission into neutral.
4. Push the start switch to crank the
engine with the starter.
Release the start switch when the
engine starts, or after 5 seconds.
Wait 10 seconds before pressing
the switch again to allow battery
voltage to restore.
NOTICE
ECA11043
For maximum engine life, never ac-
celerate hard when the engine is
cold!
UB5GE0E0.book Page 2 Thursday, August 23, 2018 10:05 AM

Periodic maintenance and adjustment
6-13
6
EAU20071
Coolant
The coolant level should be checked
before each ride. In addition, the cool-
ant must be changed at the intervals
specified in the periodic maintenance
and lubrication chart.
EAUE3460To check the coolant level
1. Place the vehicle on a level sur-
face.
2. Remove cowling C of left side.
(See page 6-7.)
3. Hold the vehicle in an upright po-
sition.
TIP
The coolant level must be
checked on a cold engine since
the level varies with engine tem-
perature.
Make sure that the vehicle is posi-
tioned straight up when checking
the coolant level. A slight tilt to the
side can result in a false reading.
4. Check the coolant level in the
coolant reservoir.
TIP
The coolant should be between the
minimum and maximum level marks.
5. If the coolant is at or below the
minimum level mark, remove the
coolant reservoir cap.
6. Add coolant to the maximum level
mark, and then install the coolant
reservoir cap. WARNING! Re-
move only the coolant reservoir
cap. Never attempt to remove
the radiator cap when the en-
gine is hot.
[EWA15162] NOTICE: If
coolant is not available, use dis-
tilled water or soft tap water in-
stead. Do not use hard water or
salt water since it is harmful to
the engine. If water has been
used instead of coolant, replace
it with coolant as soon as possi-
ble, otherwise the cooling sys-
tem will not be protected
1. Coolant reservoir
2. Maximum level mark
3. Minimum level mark
1. Coolant reservoir cap
1
2
3FULL
LOW
ZAUE3384
1
ZAUE3385
UB5GE0E0.book Page 13 Thursday, August 23, 2018 10:05 AM

Periodic maintenance and adjustment
6-36
6
EAU67131
Supporting the motorcycle
Since this model is not equipped with a
centerstand, use maintenance stands
when removing the front or rear wheel
or when performing other maintenance
that requires the motorcycle to stand
up right.
Check that the motorcycle is in a stable
and level position before starting any
maintenance.
EAU25872
Troubleshooting
Although Yamaha motorcycles receive
a thorough inspection before shipment
from the factory, trouble may occur
during operation. Any problem in the
fuel, compression, or ignition systems,
for example, can cause poor starting
and loss of power.
The following troubleshooting charts
represent quick and easy procedures
for checking these vital systems your-
self. However, should your motorcycle
require any repair, take it to a Yamaha
dealer, whose skilled technicians have
the necessary tools, experience, and
know-how to service the motorcycle
properly.
Use only genuine Yamaha replace-
ment parts. Imitation parts may look
like Yamaha parts, but they are often
inferior, have a shorter service life and
can lead to expensive repair bills.
WARNING
EWA15142
When checking the fuel system, do
not smoke, and make sure there are
no open flames or sparks in the ar-
ea, including pilot lights from water
heaters or furnaces. Gasoline or
gasoline vapors can ignite or ex-
plode, causing severe injury or prop-
erty damage.
1. Maintenance stand (example)
1
UB5GE0E0.book Page 36 Thursday, August 23, 2018 10:05 AM

Motorcycle care and storage
7-3
72. After drying the motorcycle, apply
a corrosion protection spray on all
metal, including chrome- and
nickel-plated, surfaces to prevent
corrosion.
After cleaning
1. Dry the motorcycle with a chamois
or an absorbing cloth.
2. Immediately dry the drive chain
and lubricate it to prevent it from
rusting.
3. Use a chrome polish to shine
chrome, aluminum and stainless-
steel parts, including the exhaust
system. (Even the thermally in-
duced discoloring of stainless-
steel exhaust systems can be re-
moved through polishing.)
4. To prevent corrosion, it is recom-
mended to apply a corrosion pro-
tection spray on all metal,
including chrome- and nickel-plat-
ed, surfaces.
5. Use spray oil as a universal clean-
er to remove any remaining dirt.
6. Touch up minor paint damage
caused by stones, etc.
7. Wax all painted surfaces.
8. Let the motorcycle dry completely
before storing or covering it.
WARNING
EWA11132
Contaminants on the brakes or tires
can cause loss of control.
Make sure that there is no oil or
wax on the brakes or tires.
If necessary, clean the brake
discs and brake linings with a
regular brake disc cleaner or
acetone, and wash the tires with
warm water and a mild deter-gent. Before riding at higher
speeds, test the motorcycle’s
braking performance and cor-
nering behavior.
NOTICE
ECA10801
Apply spray oil and wax spar-
ingly and make sure to wipe off
any excess.
Never apply oil or wax to any
rubber and plastic parts, but
treat them with a suitable care
product.
Avoid using abrasive polishing
compounds as they will wear
away the paint.
TIP
Consult a Yamaha dealer for ad-
vice on what products to use.
Washing, rainy weather or humid
climates can cause the headlight
lens to fog. Turning the headlight
on for a short period of time will
help remove the moisture from the
lens.
UB5GE0E0.book Page 3 Thursday, August 23, 2018 10:05 AM

10-1
10
Index
A
ABS ....................................................... 3-15
ABS warning light ................................... 3-3
Air filter element and check hose,
replacing and cleaning ....................... 6-14
B
Battery .................................................. 6-31
Brake and clutch levers, checking and
lubricating ........................................... 6-28
Brake and shift pedals, checking and
lubricating ........................................... 6-28
Brake fluid, changing ............................ 6-24
Brake fluid level, checking .................... 6-23
Brake lever ............................................ 3-14
Brake light switches.............................. 6-22
Brake pedal........................................... 3-14
Brake pedal free play, adjusting ........... 6-21
C
Cables, checking and lubricating ......... 6-27
Care ........................................................ 7-1
Catalytic converter ................................ 3-18
Clutch lever ........................................... 3-13
Clutch lever free play, adjusting ........... 6-20
Coolant ................................................. 6-13
Coolant temperature warning light ......... 3-2
Cowlings, removing and installing .......... 6-7
D
Data recording, vehicle ........................... 9-3
Diagnostic connectors ............................ 9-2
Dimmer/Pass switch ............................. 3-12
Drive chain, cleaning and lubricating .... 6-26
Drive chain slack................................... 6-25
E
Engine break-in....................................... 5-4
Engine idling speed .............................. 6-15
Engine oil and oil filter element ............. 6-10
Engine serial number .............................. 9-1
Engine stop switch ............................... 3-12
Engine trouble warning light ................... 3-3
F
Front and rear brake pads, checking.... 6-22
Front brake lever free play, checking ... 6-21
Front fork, checking .............................. 6-30
Fuel ....................................................... 3-16
Fuel consumption, tips for reducing ....... 5-4
Fuel tank cap ........................................ 3-16
Fuel tank overflow hose ........................ 3-18
Fuses, replacing.................................... 6-33
H
Handlebar switches .............................. 3-12High beam indicator light ....................... 3-2
Horn switch .......................................... 3-12
I
Identification numbers ............................ 9-1
Ignition circuit cut-off system............... 3-21
Indicator lights and warning lights ......... 3-2
L
License plate light bulb, replacing........ 6-35
M
Main switch/steering lock....................... 3-1
Maintenance and lubrication, periodic ... 6-4
Maintenance, emission control
system.................................................. 6-3
Matte color, caution ............................... 7-1
Model label ............................................. 9-1
Multi-function meter unit ........................ 3-4
N
Neutral indicator light ............................. 3-2
P
Parking ................................................... 5-5
Part locations ......................................... 2-1
S
Safety information .................................. 1-1
Seats .................................................... 3-19
Shifting ................................................... 5-3
Shift pedal ............................................ 3-13
Shift timing indicator light....................... 3-3
Sidestand ............................................. 3-20
Sidestand, checking and lubricating .... 6-29
Spark plug, checking ............................. 6-9
Specifications ......................................... 8-1
Starting the engine ................................. 5-2
Start switch .......................................... 3-12
Steering, checking................................ 6-30
Storage ................................................... 7-4
Supporting the motorcycle................... 6-36
Swingarm pivots, lubricating ................ 6-29
T
Tail/brake light ...................................... 6-34
Throttle grip and cable, checking and
lubricating .......................................... 6-27
Throttle grip free play, adjusting........... 6-15
Tires ...................................................... 6-17
Tool kit.................................................... 6-2
Troubleshooting ................................... 6-36
Troubleshooting charts ........................ 6-37
Turn signal indicator light ....................... 3-2
Turn signal light bulb, replacing ........... 6-35
Turn signal switch ................................ 3-12
UB5GE0E0.book Page 1 Thursday, August 23, 2018 10:05 AM