YAMAHA YS125 2017 Owner's Manual

Instrument and control functions
3-6
3
EAU12713
Start switch “ ”
Push this switch to crank the engine
with the starter. See page 5-1 for start-
ing instructions prior to starting the en-
gine.
EAU12822
Clutch leverThe clutch lever is located on the left
side of the handlebar. To disengage
the clutch, pull the lever toward the
handlebar grip. To engage the clutch,
release the lever. The lever should be
pulled rapidly and released slowly for
smooth clutch operation.
The clutch lever is equipped with a
clutch switch, which is part of the igni-
tion circuit cut-off system. (See page
3-13.)
EAU12872
Shift pe dalThe shift pedal is located on the left
side of the motorcycle and is used in
combination with the clutch lever when
shifting the gears of the 5-speed con-
stant-mesh transmission equipped on
this motorcycle.
1. Clutch lever
1
1. Shift pedal
1
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Instrument and control functions
3-7
3
EAU78900
Brake leverThe brake lever is located on the right
side of the handlebar. To apply the
front brake, pull the lever toward the
throttle grip.
This model is equipped with a unified
brake system.
When the brake lever is pulled, the rear
brake is also applied proportionally to
the front brake. For full braking perfor-
mance, operate the brake lever and
brake pedal simultaneously.TIP Because the unified brake system
is mechanical, additional free play
can be felt in the brake pedal when the brake lever is being
pulled, but this does not indicate a
malfunction.
 The unified brake system does not
operate when the brake pedal is
pressed down directly.
EAU78910
Brake ped alThe brake pedal is located on the right
side of the motorcycle. To apply the
rear brake, press down on the brake
pedal.TIPBecause the unified brake system is
mechanical, additional free play can be
felt in the brake pedal when the brake
lever is being pulled, but this does not
indicate a malfunction.
1. Brake lever
1
1. Brake pedal
1
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Instrument and control functions
3-8
3
EAU13003
Fuel tank capTo remove the fuel tank cap
Insert the key into the lock and turn it
1/4 turn clockwise. The lock will be re-
leased and the fuel tank cap can be re-
moved.
To install the fuel tank cap
1. Push the fuel tank cap into posi- tion with the key inserted in the
lock.
2. Turn the key counterclockwise to the original position, and then re-
move it.
TIPThe fuel tank cap cannot be installed
unless the key is in the lock. In addi-
tion, the key cannot be removed if the
cap is not properly installed and
locked.
WARNING
EWA11142
Make sure that the fuel tank cap is
properly installe d before ri din g.
Leakin g fuel is a fire hazar d.
EAU13213
FuelMake sure there is sufficient gasoline in
the tank.
WARNING
EWA10882
Gasoline an d gasoline vapors are
extremely flammab le. To avoid fires
an d explosions an d to re duce the
risk of injury when refuelin g, 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.
1. Unlock.
1
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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
3-10
3
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.
EAU13447
Catalytic converters This vehicle is equipped with catalytic
converters in the exhaust system.
WARNING
EWA10863
The exhaust system is hot after op-
eration. To prevent a fire hazar
d or
b urns:
 Do not park the vehicle near
possi ble fire hazar ds such as
g rass or other materials that
easily burn.
 Park the vehicle in a place
where pe destrians or chil dren
are not likely to touch the hot
exhaust system.
 Make sure that the exhaust sys-
tem has cooled down before
d oin g any maintenance work.
 Do not allow the en gine to id le
more than a few minutes. Lon g
i d lin g can cause a buil d-up of
heat.
NOTICE
ECA10702
Use only unlea ded g asoline. The use
of lea ded g asoline will cause unre-
paira ble damag e to the catalytic
converter.
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Instrument and control functions
3-11
3
EAU78851
SeatTo remove the seat
1. Remove panels A and B. (See page 6-8.)
2. Remove the bolts. 3. Lift the front of the seat and pull it
forward.
To install the seat 1. Insert the projection on the rear of the seat into the seat holder as
shown.
2. Place the seat in the original posi- tion, and then tighten the bolts.
3. Install the panels.
TIPMake sure that the seat is properly se-
cured before riding.
EAU68420
A djustin g the shock a bsorb er
assem blies
WARNING
EWA10211
Always a djust both shock a bsor ber
assem blies equally, otherwise poor
han dlin g an d loss of sta bility may re-
sult.Each shock absorber assembly is
equipped with a spring preload adjust-
ing ring.NOTICE
ECA10102
To avoi d d amag ing the mechanism,
d o not attempt to turn b eyond the
maximum or minimum settin gs.Adjust the spring preload as follows.
To increase the spring preload and
thereby harden the suspension, turn
the adjusting ring on each shock ab-
sorber assembly in direction (a). To de-
crease the spring preload and thereby
soften the suspension, turn the adjust-
ing ring on each shock absorber as-
sembly in direction (b).
1. Bolt
1. Bolt
1
1
1. Projection
2. Seat holder
1
2
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Instrument and control functions
3-12
3

Align the appropriate notch in the
adjusting ring with the position in-
dicator on the shock absorber.
 Use the screwdriver included in
the owner’s tool kit to make this
adjustment.
EAU15306
Sidestan dThe sidestand is located on the left
side of the frame. Raise the sidestand
or lower it with your foot while holding
the vehicle upright.TIPThe built-in sidestand switch is part of
the ignition circuit cut-off system,
which cuts the ignition in certain situa-
tions. (See the following section for an
explanation of the ignition circuit cut-
off system.)
WARNING
EWA10242
The vehicle must not b e ridden with
the si destan d d own, or if the si de-
stan d cannot b e properly move d up
(or does not stay up), otherwise the
si destan d coul d contact the groun d
an d d istract the operator, resultin g
in a possib le loss of control.
Yamaha’s ig nition circuit cut-off
system has been desi gne d to assist
the operator in fulfillin g the respon-
si bility of raisin g the si destan d b e-
fore startin g off. Therefore, check this system re
gularly an d have a
Yamaha dealer repair it if it does not
function properly.
1. Spring preload adjusting ring
2. Position indicator
3. ScrewdriverSprin g preloa d settin g:
Minimum (soft):
1
Standard: 2
Maximum (hard): 5
2
13(a)
(b)
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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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For your safety – pre-operation checks
4-1
4
EAU15599
Inspect your vehicle each time you use it to make sure the vehicle is in safe operating condition. Always follow the inspection
and maintenance procedures and schedules described in the Owner’s Manual.
WARNING
EWA11152
Failure to inspect or maintain the vehicle properly increases the possibility of an acci dent or equipment damag e.
Do not operate the vehicle if you fin d any pro blem. If a pro blem cannot be corrected b y the proce dures provi ded in
this manual, have the vehicle inspecte d b y a Yamaha dealer.Before using this vehicle, check the following points:
ITEM CHECKS PAGE
Fuel • Check fuel level in fuel tank.
• Refuel if necessary.
• Check fuel line for leakage. 3-8
En gine oil • Check oil level in engine.
• If necessary, add recommended oil to specified level.
• Check vehicle for oil leakage. 6-11
Front brake • Check operation.
• If soft or spongy, have Yamaha dealer bleed hydraulic system.
• Check brake pads for wear.
• Replace if necessary.
• Check fluid level in reservoir.
• If necessary, add specified brake fluid to specified level.
• Check hydraulic system for leakage. 6-22, 6-22
Rear brake • Check operation.
• Check pedal free play.
• Adjust if necessary. 6-21, 6-22
Clutch • Check operation.
• Lubricate cable if necessary.
• Check lever free play.
• Adjust if necessary. 6-19
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