2021 YAMAHA XSR 125 check engine

Table of contentsSafety information ............................ 1-1
Description ....................................... 2-1
Left view ......................................... 2-1
Right view ....................................... 2-2
Controls and instruments ............... 2-3
Instrument an d control functions ... 3-1
Main switch/steering lock............... 3-1
Indicator lights and warning lights............................................ 3-2
Multi-function meter unit ................ 3-4
Handlebar switches ........................ 3-9
Clutch lever .................................. 3-10
Shift pedal .................................... 3-11
Brake lever.................................... 3-11
Brake pedal .................................. 3-11
ABS .............................................. 3-12
Fuel tank cap ................................ 3-13
Fuel ............................................... 3-13
Fuel tank breather hose and overflow hose ............................ 3-15
Catalytic converter ....................... 3-16
Seat .............................................. 3-16
Helmet holder ............................... 3-17
Sidestand ..................................... 3-17
Ignition circuit cut-off system ....... 3-18 For your safety – pre-operation
checks
............................................... 4-1
Operation an d important ri din g
points ................................................. 5-1
Engine break-in ............................... 5-1
Starting the engine .......................... 5-2
Shifting ............................................ 5-3
Tips for reducing fuel consumption ................................ 5-4
Parking ............................................ 5-4
Perio dic maintenance an d
a d justment ........................................ 6-1
Tool kit ............................................ 6-2
Periodic maintenance chart for the emission control system .............. 6-3
General maintenance and lubrication chart ........................... 6-4
Removing and installing cowlings... 6-8
Checking the spark plug ................. 6-8
Canister ........................................... 6-9
Engine oil and oil filter element ..... 6-10
Why Yamalube .............................. 6-12
Coolant.......................................... 6-13
Replacing the air filter element
and cleaning the check hose..... 6-14
Adjusting the engine idling speed ......................................... 6-15
Adjusting the throttle grip free play ............................................ 6-15 Valve clearance............................. 6-16
Tires .............................................. 6-16
Cast wheels .................................. 6-18
Adjusting the clutch lever free
play ............................................ 6-18
Checking the front brake lever free play..................................... 6-19
Adjusting the brake pedal free
play ............................................ 6-20
Brake light switches ..................... 6-21
Checking the front and rear brake pads ................................ 6-21
Checking the brake fluid level ...... 6-22
Changing the brake fluid .............. 6-23
Drive chain slack........................... 6-23
Cleaning and lubricating the drive chain ................................. 6-25
Checking and lubricating the cables ........................................ 6-25
Checking and lubricating the
throttle grip and cable ............... 6-26
Checking and lubricating the brake and shift pedals............... 6-26
Checking and lubricating the brake and clutch levers ............. 6-27
Checking and lubricating the
sidestand................................... 6-27
Lubricating the rear suspension ... 6-28
Lubricating the swingarm pivots......................................... 6-28
Checking the front fork ................. 6-28UBFGE0E0.book Page 1 Friday, April 9, 2021 9:25 AM

Safety information
1-3
1Avoi
d Car bon Monoxi de Poisonin g
All engine exhaust contains carbon
monoxide, a deadly gas. Breathing
carbon monoxide can cause head-
aches, dizziness, drowsiness, nausea,
confusion, and eventually death.
Carbon Monoxide is a colorless, odor-
less, tasteless gas which may be pres-
ent even if you do not see or smell any
engine exhaust. Deadly levels of car-
bon monoxide can collect rapidly and
you can quickly be overcome and un-
able to save yourself. Also, deadly lev-
els of carbon monoxide can linger for
hours or days in enclosed or poorly
ventilated areas. If you experience any
symptoms of carbon monoxide poi-
soning, leave the area immediately, get
fresh air, and SEEK MEDICAL TREAT-
MENT.  Do not run engine indoors. Even if
you try to ventilate engine exhaust
with fans or open windows and
doors, carbon monoxide can rap-
idly reach dangerous levels.
 Do not run engine in poorly venti-
lated or partially enclosed areas
such as barns, garages, or car-
ports. 
Do not run engine outdoors where
engine exhaust can be drawn into
a building through openings such
as windows and doors.
Loa din g
Adding accessories or cargo to your
motorcycle can adversely affect stabil-
ity and handling if the weight distribu-
tion of the motorcycle is changed. To
avoid the possibility of an accident, use
extreme caution when adding cargo or
accessories to your motorcycle. Use
extra care when riding a motorcycle
that has added cargo or accessories.
Here, along with the information about
accessories below, are some general
guidelines to follow if loading cargo to
your motorcycle:
The total weight of the operator, pas-
senger, accessories and cargo must
not exceed the maximum load limit.
Operation of an overloa ded vehicle
coul d cause an acci dent. When loading within this weight limit,
keep the following in mind:
 Cargo and accessory weight
should be kept as low and close to
the motorcycle as possible. Se-
curely pack your heaviest items as
close to the center of the vehicle
as possible and make sure to dis-
tribute the weight as evenly as
possible on both sides of the mo-
torcycle to minimize imbalance or
instability.
 Shifting weights can create a sud-
den imbalance. Make sure that
accessories and cargo are se-
curely attached to the motorcycle
before riding. Check accessory
mounts and cargo restraints fre-
quently.
• Properly adjust the suspension for your load (suspension-ad-
justable models only), and
check the condition and pres-
sure of your tires.
• Never attach any large or heavy items to the handlebar, front
fork, or front fender. These
items, including such cargo as
sleeping bags, duffel bags, or
Maximum loa d:
190 kg (420 lb)
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Safety information
1-5
1operator and may limit control
ability, therefore, such accesso-
ries are not recommended.
 Use caution when adding electri-
cal accessories. If electrical ac-
cessories exceed the capacity of
the motorcycle’s electrical sys-
tem, an electric failure could re-
sult, which could cause a
dangerous loss of lights or engine
power.
Aftermarket Tires an d Rims
The tires and rims that came with your
motorcycle were designed to match
the performance capabilities and to
provide the best combination of han-
dling, braking, and comfort. Other
tires, rims, sizes, and combinations
may not be appropriate. See page 6-16
for tire specifications and for informa-
tion on servicing and replacing your
tires.
Transportin g the Motorcycle
Be sure to observe following instruc-
tions before transporting the motorcy-
cle in another vehicle. 
Remove all loose items from the
motorcycle.
 Check that the fuel cock (if
equipped) is in the off position and
that there are no fuel leaks.
 Shift the transmission into gear
(for models with a manual trans-
mission).
 Secure the motorcycle with tie-
downs or suitable straps that are
attached to solid parts of the mo-
torcycle, such as the frame or up-
per front fork triple clamp (and not,
for example, to rubber-mounted
handlebars or turn signals, or
parts that could break). Choose
the location for the straps carefully
so the straps will not rub against
painted surfaces during transport.
 The suspension should be com-
pressed somewhat by the tie-
downs, if possible, so that the mo-
torcycle will not bounce exces-
sively during transport.
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Instrument and control functions
3-2
3
To unlock the steering
From the “LOCK” position, push the
key and turn it to “OFF”.
EAU4939P
In
dicator li ghts an d warnin g
lig hts
EAUM4390
Turn si gnal in dicator li ght “ ”
This indicator light flashes when a turn
signal light is flashing.
EAU88300
Neutral in dicator li ght “ ”
This indicator light comes on when the
transmission is in the neutral position.
EAU88310
Hi gh beam in dicator li ght “ ”
This indicator light comes on when the
high beam of the headlight is switched
on.
EAUM4410
Coolant temperature warnin g
li g ht “ ”
This warning light comes on when the
engine is overheating. If this occurs,
stop the engine immediately and allow
the engine to cool. (See page 6-36.)
For vehicles with a radiator fan, the ra-
diator fan(s) automatically switch on or
off according to the coolant tempera-
ture.TIPWhen the vehicle is turned on, the light
will come on for a few seconds, and
then go off. If the light does not come
on, or if the light remains on, have a
Yamaha dealer check the vehicle.NOTICE
ECA10022
Do not continue to operate the en-
g ine if it is overheatin g.
1. Push.
2. Turn.12
1. ABS warning light “ ”
2. High beam indicator light “ ”
3. Coolant temperature warning light “ ”
4. Malfunction indicator light “ ”
5. Neutral indicator light “ ”
6. Turn signal indicator light “ ”ZAUM2012
1
2
3
4
5
6
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Instrument and control functions
3-3
3
EAU88331
Malfunction in dicator li ght
(MIL) “ ”
This light comes on or flashes if a prob-
lem is detected in the engine or other
vehicle control system. If this occurs,
have a Yamaha dealer check the on-
board diagnostic system. The electri-
cal circuit of the warning light can be
checked by turning the vehicle power
on. The light should come on for a few
seconds, and then go off. If the light
does not come on initially when the ve-
hicle power is turned on, or if the light
remains on, have a Yamaha dealer
check the vehicle.NOTICE
ECA26820
If the MIL starts flashin g, re duce en-
g ine speed to prevent exhaust sys-
tem damag e.TIPThe engine is sensitively monitored by
the on-board diagnostic system to de-
tect deterioration or malfunction of the
emission control system. Therefore the
MIL may come on or flash due to vehi-
cle modifications, lack of maintenance, or excessive/improper use of the mo-
torcycle. To prevent this, observe
these precautions.
 Do not attempt to modify the soft-
ware of the engine control unit.
 Do not add any electrical acces-
sories that interfere with engine
control.
 Do not use aftermarket accesso-
ries or parts such as suspension,
spark plugs, injectors, exhaust
system, etc.
 Do not change the drivetrain
specifications (chain, sprockets,
wheels, tires, etc.).
 Do not remove or alter the O2 sen-
sor, air induction system, or ex-
haust parts (catalysts or EXUP,
etc.).
 Maintain the drive chain properly.
 Maintain correct tire pressure.
 Maintain proper brake pedal
height to prevent rear brake from
dragging.
 Do not operate the vehicle in an
extreme manner. For example, re-
peated or excessive opening and closing of the throttle, racing,
burnouts, wheelies, extended
half-clutch use, etc.
EAU88342
ABS warnin
g li ght “ ”
In normal operation, the ABS warning
light comes on when the vehicle is
turned on, and goes off after traveling
at a speed of 10 km/h (6 mi/h) or high-
er.TIPIf the warning light does not work as
described above, or if the warning light
comes on while riding, the ABS may
not work correctly. Have a Yamaha
dealer check the vehicle as soon as
possible.
WARNING
EWA16043
If the ABS warnin g li ght does not
turn off after reachin g 10 km/h (6
mi/h), or if the warnin g li ght comes
on while ri din g:
 Use extra caution to avoi d pos-
si ble wheel lock d uring emer-
g ency brakin g.
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Instrument and control functions
3-5
3 The speedometer shows the vehicle’s
traveling speed.
EAU87170
Tachometer
The tachometer allows the rider to
monitor the engine speed and keep it
within the ideal power range.NOTICE
ECA10032
Do not operate the en
gine in the ta-
chometer red zone.
Re d zone: 11000 r/min an d a bove
EAU86841
Fuel meter
The fuel meter indicates the amount of
fuel in the fuel tank. The display seg-
ments of the fuel meter disappear from
“F” (full) towards “E” (empty) as the fuel
level decreases. When approximately
3.0 L (0.79 US gal, 0.66 Imp.gal) of fuel
remains, the last segment starts flash-
ing. Refuel as soon as possible.TIPIf a problem is detected in the electrical
circuit, the fuel level segments will flash
repeatedly. If this occurs, have a
Yamaha dealer check the vehicle.
EAU87370
VVA in dicator
This model is equipped with variable
valve actuation (VVA) for good fuel
economy and acceleration in both the
low-speed and high-speed ranges.
The VVA indicator comes on when the
variable valve actuation system has
switched to the high-speed range.
1. Tachometer
2. Red zoneZAUM2015
1 2
1. Fuel meterZAUM2016
1
1. VVA (variable valve actuation) indicatorZAUM2017
1
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Instrument and control functions
3-18
3
this system re
gularly an d have a
Yamaha dealer repair it if it does not
function properly.
EAU44895
I g nition circuit cut-off systemThis system prevents in-gear engine
starts unless the clutch lever is pulled
and the sidestand is up. Also, it will
stop the running engine should the
sidestand be lowered while the trans-
mission is in gear.
Periodically check the system via the
following procedure.TIP This check is most reliable if per-
formed with a warmed-up engine.
 See pages 3-1 and 3-9 for switch
operation information.
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Instrument and control functions
3-19
3
With the engine turned off:
1. Move the sidestand down.
2. Set engine stop switch to run position.
3. Turn main switch to on position.
4. Shift transmission into neutral.
5. Push the start switch.
Does the engine start?
With the engine still running:
6. Move the sidestand up.
7. Pull the clutch lever.
8. Shift transmission into gear.
9. Move the sidestand down.
Does the engine stall?
After the engine has stalled:
10. Move the sidestand up.
11. Pull the clutch lever.
12. Push the start switch.
Does the engine start?
The system is OK. The motorcycle can be ridden.
YES NO YES NO YES NO
The neutral switch may not be working.
The motorcycle should not be ridden until
checked by a Yamaha dealer.
The clutch switch may not be working.
The motorcycle should not be ridden until
checked by a Yamaha dealer.The sidestand switch may not be working.
The motorcycle should not be ridden until
checked by a Yamaha dealer.If a malfunction is found, have the vehicle
inspected before riding.
WARNING
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