light YAMAHA YS125 2017 User Guide

Operation and important rid ing points
5-1
5
EAU15952
Read the Owner’s Manual carefully to
become familiar with all controls. If
there is a control or function you do not
understand, ask your Yamaha dealer.
WARNING
EWA10272
Failure to familiarize yourself with
the controls can lead to loss of con-
trol, which coul d cause an acci dent
or injury.
EAUM3150
TIPThis model is equipped with a lean an-
gle sensor to stop the engine in case of
a turnover. To start the engine after a
turnover, be sure to turn the main
switch to “ ” and then to “ ”. Failing
to do so will prevent the engine from
starting even though the engine will
crank when pushing the start switch.
EAU78350
Startin g the en gineIn order for the ignition circuit cut-off
system to enable starting, one of the
following conditions must be met:
 The transmission is in the neutral
position.
 The transmission is in gear with
the clutch lever pulled and the
sidestand up.
See page 3-13 for more informa-
tion.
1. Turn the key to “ ”. The engine trouble warning light
should come on for a few sec-
onds, then go off.NOTICE
ECA23970
If the warnin g li ght does not come
on initially when the key is turne d
to “ ”, or if the warnin g li ght re-
mains on, see pag e 3-2 for the warn-
in g lig ht circuit check.2. Shift the transmission into the
neutral position. The neutral indi-
cator light should come on. If not,
ask a Yamaha dealer to check the
electrical circuit.
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Operation and important ri din g points
5-2
5
3. Start the engine by pushing the
start switch.
If the engine fails to start when us-
ing the start switch, release it, wait
a few seconds, and then try again.
Each starting attempt should be
as short as possible to preserve
the battery. Do not crank the en-
gine more than 10 seconds on any
one attempt.
NOTICE
ECA11043
For maximum en gine life, never ac-
celerate har d when the en gine is
col d!
EAU16673
Shiftin gShifting gears lets you control the
amount of engine power available for
starting off, accelerating, climbing hills,
etc.
The gear positions are shown in the il-
lustration.TIPTo shift the transmission into the neu-
tral position, press the shift pedal down
repeatedly until it reaches the end of its
travel, and then slightly raise it.
NOTICE
ECA10261
Even with the transmission in
the neutral position, d o not
coast for lon g period s of time
with the en gine off, an d d o not
tow the motorcycle for lon g d is-
tances. The transmission is
properly lu bricated only when
the en gine is runnin g. Ina de-
quate lu brication may d amage
the transmission.
 Always use the clutch while
chan gin g g ears to avoi d d am-
a g in g the en gine, transmission,
an d d rive train, which are not
d esi gne d to withstan d the
shock of force d shiftin g.
1. Shift pedal
2. Neutral position
1
N
2 3
4
5
1
2
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Operation and important rid ing points
5-3
5
EAU16811
Tips for re ducin g fuel con-
sumptionFuel consumption depends largely on
your riding style. Consider the follow-
ing tips to reduce fuel consumption:
 Shift up swiftly, and avoid high en-
gine speeds during acceleration.
 Do not rev the engine while shift-
ing down, and avoid high engine
speeds with no load on the en-
gine.
 Turn the engine off instead of let-
ting it idle for an extended length
of time (e.g., in traffic jams, at traf-
fic lights or at railroad crossings).
EAU16831
Engine break-inThere is never a more important period
in the life of your engine than the period
between 0 and 1000 km (600 mi). For
this reason, you should read the fol-
lowing material carefully.
Since the engine is brand new, do not
put an excessive load on it for the first
1000 km (600 mi). The various parts in
the engine wear and polish themselves
to the correct operating clearances.
During this period, prolonged full-throt-
tle operation or any condition that
might result in engine overheating
must be avoided.
EAU16883
0–150 km (0–90 mi)
Avoid prolonged operation above 4500
r/min.
After every hour of operation, stop the
engine, and then let it cool for five to
ten minutes.
Vary the engine speed from time to
time. Do not operate the engine at one
set throttle position. 150–500 km (90–300 mi)
Avoid prolonged operation above 5400
r/min.
Rev the engine freely through the
gears, but do not use full throttle at any
time.
500–1000 km (300–600 mi)
Avoid prolonged full-throttle operation.
Avoid prolonged operation above 7000
r/min.
NOTICE: After 1000 km (600
mi) of operation, the en gine oil must
b e chan ged an d the oil filter car-
tri dge or element replace d.
[ECA10303]
1000 km (600 mi) an d b eyon d
The vehicle can now be operated nor-
mally.NOTICE
ECA10311
 Keep the en gine spee d out of
the tachometer red zone.
 If any en gine trou ble shoul d oc-
cur during the en gine break-in
period , imme diately have a
Yamaha dealer check the vehi-
cle.
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Periodic maintenance an d a djustment
6-7
6
EAU72690
TIP The air filter needs more frequent service if you are riding in unusually wet or dusty areas.
 Hydraulic brake service
• Regularly check and, if necessary, correct the brake fluid level.
• Every two years replace the internal components of the brake master cylinder and caliper, and change the brake fluid.
• Replace the brake hoses every four years and if cracked or damaged.29 *Throttle
grip hous-
in g an d cab le • Check operation and free play.
• Adjust the throttle cable free play
if necessary.
• Lubricate the throttle grip housing and cable. √√√√√
30 *Li
ghts, si gnals an d
switches • Check operation.
• Adjust headlight beam.
√√√√√√
NO. ITEM CHECK OR MAINTENANCE JOB
ODOMETER READING
ANNUAL
CHECK
1000 km
(600 mi) 6000 km
(3500 mi) 12000 km
(7000 mi) 18000 km
(10500 mi) 24000 km
(14000 mi)UBT4E0E0.book Page 7 Thursday, November 17, 2016 10:55 AM

Periodic maintenance an d a djustment
6-10
6
EAU78710
Checkin g the spark plugThe spark plug is an important engine
component, which is easy to check.
Since heat and deposits will cause any
spark plug to slowly erode, the spark
plug should be removed and checked
in accordance with the periodic main-
tenance and lubrication chart. In addi-
tion, the condition of the spark plug
can reveal the condition of the engine.
To remove the spark plu g
1. Remove cowling A. (See page 6-8.)
2. Remove the Y.R.C.S. (Yamaha Ram-Air Cooling System) cap by
removing the bolts and then, re-
move the spark plug cap. 3. Remove the spark plug as shown,
with the spark plug wrench includ-
ed in the owner’s tool kit. To check the spark plu
g
1. Check that the porcelain insulator around the center electrode of the
spark plug is a medium-to-light
tan (the ideal color when the vehi-
cle is ridden normally).
TIPIf the spark plug shows a distinctly dif-
ferent color, the engine could be oper-
ating improperly. Do not attempt to
diagnose such problems yourself. In-
stead, have a Yamaha dealer check
the vehicle.2. Check the spark plug for electrodeerosion and excessive carbon or
other deposits, and replace it if
necessary.
3. Measure the spark plug gap with a wire thickness gauge and, if nec-
essary, adjust the gap to specifi-
cation.
1. Cowling A
2. Y.R.C.S (Yamaha Ram–Air Cooling System) cap
3. Bolt
4. Spark plug cap
1. Spark plug wrench
4 32
1
1
Specified
spark plu g:
NGK/CPR8EA-9
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Periodic maintenance an d a djustment
6-11
6
To install the spark plu g
1. Clean the surface of the spark plug gasket and its mating surfa-
ce, and then wipe off any grime
from the spark plug threads.
2. Install the spark plug with the spark plug wrench, and then tight-
en it to the specified torque.
TIPIf a torque wrench is not available
when installing a spark plug, a good
estimate of the correct torque is 1/4–
1/2 turn past finger tight. However, the
spark plug should be tightened to the
specified torque as soon as possible.3. Install the spark plug cap.
4. Install the Y.R.C.S. (Yamaha Ram-Air Cooling System) cap by install-
ing the bolts.
5. Install the cowling.
EAU78803
En gine oil an d oil filter ele-
mentThe engine oil level should be checked
before each ride. In addition, the oil
must be changed and the oil filter ele-
ment replaced at the intervals specified
in the periodic maintenance and lubri-
cation chart.
To check the en gine oil level
1. Place the vehicle on the center- stand. A slight tilt to the side can
result in a false reading.
2. Start the engine, warm it up for several minutes, and then turn it
off.
3. Wait a few minutes until the oil set- tles, remove the engine oil filler
cap, wipe the dipstick clean, insert
it back into the oil filler hole (with-
out screwing it in), and then re-
move it again to check the oil level.
WARNING! Never remove the
engine oil filler cap after hi gh-
speed operation, otherwise hot
en gine oil coul d spout out an d
cause damag e or injury. Always
let the en gine oil cool down suf-
1. Spark plug gapSpark plu g g ap:
0.8–0.9 mm (0.031–0.035 in)
Ti ghtenin g torque:
Spark plug: 13 N·m (1.3 kgf·m, 9.4 lb·ft)
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Periodic maintenance an d a djustment
6-15
6 3. Lightly tap the air filter element to
remove most of the dust and dirt,
and then blow the remaining dirt
out with compressed air as
shown.
TIPReplace the air filter element if it is ex-
cessively worn or damaged.4. Insert the air filter element into theair filter case. NOTICE: Make
sure that the air filter element is
properly seate d in the air filter
case. The en gine shoul d never
b e operated without the air filter
element installe d, otherwise the piston(s) an
d/or cylin der(s) may
b ecome excessively worn.
[ECA10482]
5. Install the air filter case cover by
installing the screws.
6. Install the panel.
To clean the air filter check hose 1. Remove panel A. (See page 6-8.)
2. Check the hose shown for accu- mulated dirt, water or oil. 3. If dirt, water or oil is visible, re-
move the hose, clean it, and then
install it in its original position.
4. Install the panel.
1. Air filter element
1
1. Air filter element
1
1. Air filter check hose
1
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Periodic maintenance an d a djustment
6-21
6
EAU39815
A djustin g the brake pe dal free
playMeasure the brake pedal free play at
the brake pedal end as shown.
Periodically check the brake pedal free
play and, if necessary, adjust it as fol-
lows.
To increase the brake pedal free play,
turn the brake pedal free play adjusting
nut at the brake rod in direction (a). To
decrease the brake pedal free play,
turn the adjusting nut in direction (b).
WARNING
EWA10681
 After a djustin g the drive chain
slack or removin g an d installin g
the rear wheel, always check
the brake pe dal free play.
 If proper a djustment cannot b e
o btaine d as descri bed , have a
Yamaha dealer make this ad -
justment.
 After a djustin g the brake ped al
free play, check the operation of
the brake li ght.
EAU22274
Brake li ght switchesThe brake light, which is activated by
the brake pedal and brake lever,
should come on just before braking
takes effect. If necessary, adjust the
rear brake light switch as follows, but
the front brake light switch should be
adjusted by a Yamaha dealer.
Turn the rear brake light switch adjust-
ing nut while holding the rear brake
light switch in place. To make the
brake light come on earlier, turn the ad-
justing nut in direction (a). To make the
brake light come on later, turn the ad-
justing nut in direction (b).
1. Brake pedal free playBrake pe dal free play:
10.0–20.0 mm (0.39–0.79 in)
1
1. Brake pedal free play adjusting nut
1
(a)
(b)
1. Rear brake light switch
2. Rear brake light switch adjusting nut
1 2
(a)
(b)
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Periodic maintenance an d a djustment
6-33
6
EAU78872
Replacin g the hea dlig ht bul bThis model is equipped with a halogen
bulb headlight. If the headlight bulb
burns out, replace it as follows.NOTICE
ECA10651
Take care not to d amage the follow-
in g parts:
 Hea dlig ht bul b
Do not touch the g lass part of
the hea dlig ht bul b to keep it free
from oil, otherwise the transpar-
ency of the glass, the luminosity
of the b ulb, an d the bul b life will
b e ad versely affected . Thor-
ou ghly clean off any dirt an d fin-
g erprints on the head lig ht bul b
usin g a cloth moistened with al-
cohol or thinner.
 Hea dlig ht lens
Do not affix any type of tinted
film or stickers to the hea dlig ht
lens.
Do not use a hea dlig ht bul b of a
watta ge hi gher than specifie d.
1. Remove the headlight unit side
covers by removing the screw on
each side. 2. Remove the bolt on each side.
3. Loosen the headlight unit stay
bolt, and then tilt the headlight unit
forward.1. Do not touch the glass part of the bulb.
1. Headlight unit side cover
2. Screw
1
2
1. Headlight unit side cover
2. Screw
3. Headlight unit stay bolt
1. Bolt
213
1
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Periodic maintenance an d a djustment
6-34
6
4. Disconnect the headlight coupler,
then remove the headlight bulb
cover.
5. Unhook the headlight bulb holder, then remove the burnt-out bulb. 6. Place a new headlight bulb into
position, then secure it with the
bulb holder.
7. Install the headlight bulb cover, then connect the headlight cou-
pler.
8. Place the headlight unit in its orig- inal position, and then tighten the
headlight unit stay bolt to the
specified torque.
9. Install the bolt on each side.
10. Place the headlight unit side cov- ers in their original position, and
then install the screw on each
side.
11. Have a Yamaha dealer adjust the headlight beam if necessary.
EAU45226
Replacin g the auxiliary li ght
b ul b If the auxiliary light bulb burns out, re-
place it as follows.
1. Remove the headlight unit. (See page 6-33.)
2. Remove the auxiliary light bulb socket (together with the bulb) by
pulling it out.
3. Remove the burnt-out bulb by pulling it out.
4. Insert a new bulb into the socket.
5. Install the socket (together with the bulb) by pushing it in.
6. Install the headlight unit.
1. Headlight coupler
2. Headlight bulb holder
1. Headlight bulb holder
2. Headlight bulb
1 21
2
Ti
ghtenin g torque:
Headlight unit stay bolt: 7 N·m (0.7 kgf·m, 5.1 lb·ft)
1. Auxiliary light bulb
2. Auxiliary light bulb socket
1
2
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