2017 YAMAHA YS125 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 light ............................................. 3-2
Multi-function meter unit ................ 3-3
Handlebar switches ........................ 3-5
Clutch lever .................................... 3-6
Shift pedal ...................................... 3-6
Brake lever...................................... 3-7
Brake pedal .................................... 3-7
Fuel tank cap .................................. 3-8
Fuel ................................................. 3-8
Catalytic converters ..................... 3-10
Seat .............................................. 3-11
Adjusting the shock absorber assemblies ................................ 3-11
Sidestand ..................................... 3-12
Ignition circuit cut-off system ....... 3-13 For your safety – pre-operation
checks
............................................... 4-1
Operation an d important ri din g
points ................................................. 5-1
Starting the engine .......................... 5-1
Shifting ............................................ 5-2
Tips for reducing fuel consumption ................................ 5-3
Engine break-in ............................... 5-3
Parking ............................................ 5-4
Perio dic maintenance an d
a d justment ........................................ 6-1
Owner’s tool kit ............................... 6-2
Periodic maintenance chart for the emission control system .............. 6-3
General maintenance and lubrication chart ........................... 6-4
Removing and installing the
cowling and panels ...................... 6-8
Checking the spark plug ............... 6-10
Engine oil and oil filter element ..... 6-11
Cleaning the air filter element and cleaning the check hose ............ 6-14
Adjusting the engine idling
speed ......................................... 6-16
Checking the throttle grip free play ............................................ 6-16
Valve clearance ............................. 6-17
Tires .............................................. 6-17 Cast wheels .................................. 6-19
Adjusting the clutch lever free
play ............................................ 6-19
Checking the brake lever free play ............................................ 6-20
Adjusting the brake pedal free play ............................................ 6-21
Brake light switches ..................... 6-21
Checking the front brake pads
and rear brake shoes ............... 6-22
Checking the brake fluid level ...... 6-22
Changing the brake fluid ............. 6-23
Drive chain slack........................... 6-24
Cleaning and lubricating the
drive chain ................................. 6-25
Checking and lubricating the cables ........................................ 6-26
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 centerstand and sidestand........ 6-28
Lubricating the swingarm
pivots......................................... 6-28
Checking the front fork ................. 6-29
Checking the steering................... 6-29
Checking the wheel bearings ....... 6-30
Battery .......................................... 6-30UBT4E0E0.book Page 1 Thursday, November 17, 2016 10:55 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:
171 kg (377 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. Refer to page
6-17 for tire specifications and more in-
formation on 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.
 Point the front wheel straight
ahead on the trailer or in the truck
bed, and choke it in a rail to pre-
vent movement.
 Shift the transmission in gear (for
models with a manual transmis-
sion).
 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
Insert the key and turn it to “ ”.
EAU1100D
In
dicator li ghts an d warnin g
lig ht
EAU11022
Turn si gnal in dicator li ght “ ”
This indicator light flashes when a turn
signal light is flashing.
EAU11061
Neutral in dicator li ght “ ”
This indicator light comes on when the
transmission is in the neutral position.
EAU11081
Hi gh beam in dicator li ght “ ”
This indicator light comes on when the
high beam of the headlight is switched
on.
EAU78310
En gine trou ble warnin g li ght “ ”
This warning light comes on 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 electrical circuit of the warning
light can be checked by turning the key
to “ ”. The warning light should come
on for a few seconds, and then go off.
If the warning light does not come on
initially when the key is turned to “ ”,
or if the warning light remains on, have
a Yamaha dealer check the vehicle.
EAUE2572
Eco in dicator li ght “ECO”
This indicator light comes on when the
vehicle is being operated in an environ-
mentally friendly, fuel-efficient manner.
The indicator light goes off when the
vehicle is stopped.
1. Turn.
1
1. Turn signal indicator light “ ”
2. Neutral indicator light “ ”
3. High beam indicator light “ ”
4. Eco indicator light “ECO”
5. Engine trouble warning light “ ”
1
2
3
4
5
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Instrument and control functions
3-4
3
O
dometer an d tripmeter
The odometer shows the total distance
traveled by the vehicle.
The tripmeter shows the distance trav-
eled since it was last reset.
TIP The odometer will lock at 999999.
 The tripmeter will reset and conti-
nue counting after 9999.9 is
reached.Pushing the “RESET/SELECT” button
switches the display between the
odometer “ODO” and the tripmeter
“TRIP”. To reset the tripmeter, select it by
pushing the “RESET/SELECT” button,
and then push the “RESET/SELECT”
button for one second.
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: 9000 r/min an d a bove
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 the last seg-
ment of the fuel meter and the fuel level
warning indicator “ ” start flashing,
refuel as soon as possible.TIPIf a problem is detected in the fuel me-
ter electrical circuit, all the display seg-
ments and the fuel level warning
indicator “ ” start flashing. If this oc-
curs, have a Yamaha dealer check the
electrical circuit.
1. Odometer/tripmeter
1
1. Tachometer
2. Tachometer red zone1 2
1. Fuel level warning indicator “ ”
2. Fuel meter
1
2
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Instrument and control functions
3-9
3
3. Wipe up any spilled fuel immedi-ately. NOTICE: Immediately
wipe off spille d fuel with a clean,
d ry, soft cloth, since fuel may
d eteriorate painted surfaces or
plastic parts.
[ECA10072]
4. Be sure to securely close the fuel tank cap.
WARNING
EWA15152
Gasoline is poisonous an d can cau-
se injury or death. Han dle gasoline
with care. Never siphon gasoline by
mouth. If you shoul d swallow some
g asoline or inhale a lot of g asoline
vapor, or g et some gasoline in your
eyes, see your d octor immediately. If g
asoline spills on your skin, wash
with soap an d water. If g asoline
spills on your clothin g, chan ge your
clothes.
EAU76860
NOTICE
ECA11401
Use only unlea ded g asoline. The use
of lea ded g asoline will cause severe
d amag e to internal en gine parts,
such as the valves an d piston rin gs,
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 regular unleaded gaso-
line with a research octane number of
95 or higher. If knocking (or pinging)
occurs, use a gasoline of a different
brand or premium unleaded fuel. Use
of unleaded fuel will extend spark plug
life and reduce maintenance costs.
1. Fuel tank filler tube
2. Maximum fuel level
1
2
Recommen ded fuel:
Regular unleaded gasoline (Gasohol
[E10] acceptable)
Fuel tank capacity:
14 L (3.7 US gal, 3.1 Imp.gal)
Fuel reserve amount: 2.2 L (0.58 US gal, 0.48 Imp.gal)
E10
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Instrument and control functions
3-13
3
EAU78340
Ig nition circuit cut-off systemThe ignition circuit cut-off system
(comprising the sidestand switch,
clutch switch and neutral switch) has
the following functions.
 It prevents starting when the
transmission is in gear and the
sidestand is up, but the clutch le-
ver is not pulled.
 It prevents starting when the
transmission is in gear and the
clutch lever is pulled, but the side-
stand is still down.
 It cuts the running engine when
the transmission is in gear and the
sidestand is moved down.
Periodically check the operation of the
ignition circuit cut-off system accord-
ing to the following procedure.UBT4E0E0.book Page 13 Thursday, November 17, 2016 10:55 AM

Instrument and control functions
3-14
3
With the engine turned off:
1. Move the sidestand down.
2. Turn the key on.
3. Shift the transmission into the neutral position.
4. Push the start switch.
Does the engine start?
With the engine still running:
5. Move the sidestand up.
6. Keep the clutch lever pulled.
7. Shift the transmission into gear.
8. Move the sidestand down.
Does the engine stall?
After the engine has stalled:
9. Move the sidestand up.
10. Keep the clutch lever pulled.
11. Push the start switch.
Does the engine start?
The system is OK. The motorcycle can be ridden. The sidestand switch may not be working correctly.
The motorcycle should not be ridden
until
checked by a Yamaha dealer.
The clutch switch may not be working correctly.
The motorcycle should not be ridden until
checked by a Yamaha dealer.
YES NO YES NO YES NO
The neutral switch may not be working correctly.
The motorcycle should not be ridden until
checked by a Yamaha dealer. The vehicle must be placed on the center-
stand during this inspection.If a malfunction is noted, have a Yamaha
dealer check the system before riding.
WA R N I N G
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