2017 YAMAHA YS125 maintenance

Periodic maintenance an d a djustment
6-12
6
ficiently
before removin g the oil
filler cap.
[EWA17640]
NOTICE: Do not
operate the vehicle until you
know that the en gine oil level is
sufficient.
[ECA10012]
TIPThe engine oil should be between the
minimum and maximum level marks.4. If the engine oil is below the mini- mum level mark, add sufficient oil
of the recommended type to raise
it to the correct level.
5. Check the O-ring for damage, and replace it if necessary.
6. Install and tighten the engine oil filler cap.
To chan ge the en gine oil (with or
without oil filter element replace-
ment) 1. Start the engine, warm it up for several minutes, and then turn it
off.
2. Place an oil pan under the engine to collect the used oil.
3. Remove the engine oil filler cap, the engine oil drain bolt and its
gasket to drain the oil from the
crankcase.
TIPSkip steps 4–6 if the oil filter element is
not being replaced.4. Remove the oil filter element coverby removing the bolts.
1. Engine oil filler cap
1. O-ring
2. Engine oil dipstick
3. Maximum level mark
4. Minimum level mark
1
4 321
1. Engine oil drain bolt
2. Gasket
1. Bolt
2. Oil filter element cover
12
1
2
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Periodic maintenance an d a djustment
6-13
6 5. Remove and replace the oil filter
element and O-ring.
6. Install the oil filter element cover by installing the bolts, then tight-
ening them to the specified
torque.
TIPMake sure that the O-ring is properly
seated.7. Install the engine oil drain bolt andits new gasket, and then tighten
the bolt to the specified torque. 8. Refill with the specified amount of
the recommended engine oil.
NOTICE
ECA11621
In or der to prevent clutch slip-
pa ge (since the en gine oil also
lu bricates the clutch), do not
mix any chemical additives. Do
not use oils with a diesel speci-
fication of “CD” or oils of a hi gh-
er quality than specifie d. In
a ddition, do not use oils la beled
“ENERGY CONSERVING II” or
hi gher.
 Make sure that no forei gn mate-
rial enters the crankcase.
9. Check the O-ring for damage, and replace it if necessary.
10. Install and tighten the engine oil filler cap.NOTICE
ECA10441
After chan gin g the en gine oil, b e
sure to check the oil pressure as de-
scri bed b elow.To check the oil pressure
1. Remove cowling A. (See page 6-8.)
2. Remove the Y.R.C.S. (Yamaha Ram-Air Cooling System) cap.
(See page 6-10.)
1. Oil filter element
2. O-ringTightenin g torque:
Oil filter element cover bolt: 10 N·m (1.0 kgf·m, 7.2 lb·ft)
2 1
Ti
ghtenin g torque:
Engine oil drain bolt:
20 N·m (2.0 kgf·m, 14 lb·ft)
Recommen ded en gine oil:
See page 8-1.
Oil quantity:
Oil change:1.00 L (1.06 US qt, 0.88 Imp.qt)
With oil filter removal:
1.10 L (1.16 US qt, 0.97 Imp.qt)
1. Engine oil filler cap
2. O-ring
21
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Periodic maintenance an d a djustment
6-14
6
3. Loosen the bleed bolt, start the
engine and keep it idling until oil
flows out. If no oil comes out after
several minutes, turn the engine
off immediately and consult a
Yamaha dealer for inspection.
4. After checking the oil pressure, tighten the bleed bolt with the
specified torque.
5. Install the Y.R.C.S. (Yamaha Ram- Air Cooling System) cap.
6. Install the cowling. 7. Start the engine, and then let it idle
for several minutes while checking
it for oil leakage. If oil is leaking,
immediately turn the engine off
and check for the cause.
8. Turn the engine off, check the oil level and correct it if necessary.
EAUW3321
Cleanin g the air filter element
an d cleanin g the check hoseThe air filter element should be cleaned
at the intervals specified in the periodic
maintenance and lubrication chart.
Clean the air filter element more fre-
quently if you are riding in unusually
wet or dusty areas. In addition, the air
filter check hose must be frequently
checked and cleaned if necessary.
To clean the air filter element
1. Remove panel A. (See page 6-8.)
2. Remove the air filter case cover by removing the screws, and then
pull the air filter element out.
1. Bleed boltTightenin g torque:
Bleed bolt: 7 N·m (0.7 kgf·m, 5.1 lb·ft)
1
1. Air filter case cover
2. Screw
2 2
1
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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
6-16
6
EAU34302
A djustin g the en gine i dlin g
spee dThe engine idling speed must be
checked and, if necessary, adjusted as
follows at the intervals specified in the
periodic maintenance and lubrication
chart.
The engine should be warm before
making this adjustment.
Check the engine idling speed and, if
necessary, adjust it to specification by
turning the idle adjusting screw. To in-
crease the engine idling speed, turn
the screw in direction (a). To decrease
the engine idling speed, turn the screw
in direction (b).
TIPIf the specified idling speed cannot be
obtained as described above, have a
Yamaha dealer make the adjustment.
EAU21386
Checkin g the throttle grip free
playMeasure the throttle grip free play as
shown.
Periodically check the throttle grip free
play and, if necessary, have a Yamaha
dealer adjust it.
1. Idle adjusting screw
1
(b)
(a)
En gine i dlin g spee d:
1300–1500 r/min
1. Throttle grip free play
Throttle grip free play:
3.0–7.0 mm (0.12–0.28 in)
1
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Periodic maintenance and adjustment
6-17
6
EAU21402
Valve clearanceThe valve clearance changes with use,
resulting in improper air-fuel mixture
and/or engine noise. To prevent this
from occurring, the valve clearance
must be adjusted by a Yamaha dealer
at the intervals specified in the periodic
maintenance and lubrication chart.
EAU69760
TiresTires are the only contact between the
vehicle and the road. Safety in all con-
ditions of riding depends on a relatively
small area of road contact. Therefore, it
is essential to maintain the tires in good
condition at all times and replace them
at the appropriate time with the speci-
fied tires.
Tire air pressure
The tire air pressure should be
checked and, if necessary, adjusted
before each ride.
WARNING
EWA10504
Operation of this vehicle with im-
proper tire pressure may cause se-
vere injury or death from loss of
control. The tire air pressure must be
checked and adjusted on cold
tires (i.e., when the temperature
of the tires equals the ambient
temperature).
 The tire air pressure must be
adjusted in accordance with the
riding speed and with the total weight of rider, passenger, car-
go, and accessories approved
for this model.
WARNING
EWA10512
Never overload your vehicle. Opera-
tion of an overloaded vehicle could
cause an accident.Tire air pressure (measured on cold
tires):
1 person:Front:
175 kPa (1.75 kgf/cm², 25 psi)
Rear: 200 kPa (2.00 kgf/cm², 29 psi)
2 persons: Front:175 kPa (1.75 kgf/cm², 25 psi)
Rear: 225 kPa (2.25 kgf/cm², 33 psi)
Maximum load:
Front:175 kPa (1.75 kgf/cm², 25 psi)
Rear:
250 kPa (2.50 kgf/cm², 36 psi)
Maximum load*: 171 kg (377 lb)
* Total weight of rider, passenger, car- go and accessories
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Periodic maintenance an d a djustment
6-18
6
Tire inspection
The tires must be checked before each
ride. If the center tread depth reaches
the specified limit, if the tire has a nail
or glass fragments in it, or if the side-
wall is cracked, have a Yamaha dealer
replace the tire immediately.
TIPThe tire tread depth limits may differ
from country to country. Always com-
ply with the local regulations.
WARNING
EWA10472

Have a Yamaha d ealer replace
excessively worn tires. Besi des
b ein g ille gal, operatin g the vehi-
cle with excessively worn tires
d ecreases ri din g sta bility an d
can lea d to loss of control.
 The replacement of all wheel
and b rake-relate d parts, inclu d-
in g the tires, shoul d b e left to a
Yamaha dealer, who has the
necessary professional knowl-
e dg e an d experience to do so.
 Ride at mo derate spee ds after
chan gin g a tire since the tire
surface must first be “ broken
in” for it to d evelop its optimal
characteristics.Tire information
This model is equipped with tubeless
tires and rubber tire air valves.
Tires age, even if they have not been
used or have only been used occasion-
ally. Cracking of the tread and sidewall
rubber, sometimes accompanied by
carcass deformation, is an evidence of ageing. Old and aged tires shall be
checked by tire specialists to ascertain
their suitability for further use.
WARNING
EWA10462
The front an
d rear tires shoul d b e of
the same make an d d esi gn, other-
wise the han dlin g characteristics of
the vehicle may be different, which
coul d lea d to an acci dent.After extensive tests, only the tires list-
ed below have been approved for this
model by Yamaha.
1. Tire sidewall
2. Tire tread depthMinimum tire trea d d epth (front an d
rear): 1.6 mm (0.06 in)
Front tire:Size: 2.75-18M/C 42P
Manufacturer/model: CHENG SHIN/C910
Rear tire:
Size: 100/80-18M/C 59P
Manufacturer/model:
CHENG SHIN/C905
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Periodic maintenance an d a djustment
6-19
6
EAU21963
Cast wheelsTo maximize the performance, durabil-
ity, and safe operation of your vehicle,
note the following points regarding the
specified wheels.
 The wheel rims should be
checked for cracks, bends, warp-
age or other damage before each
ride. If any damage is found, have
a Yamaha dealer replace the
wheel. Do not attempt even the
smallest repair to the wheel. A de-
formed or cracked wheel must be
replaced.
 The wheel should be balanced
whenever either the tire or wheel
has been changed or replaced. An
unbalanced wheel can result in
poor performance, adverse han-
dling characteristics, and a short-
ened tire life.
EAU51253
Adjustin g the clutch lever free
playMeasure the clutch lever free play as
shown.
Periodically check the clutch lever free
play and, if necessary, adjust it as fol-
lows.
1. Slide back the rubber cover at the clutch lever.
2. Loosen the locknut. 3. To increase the clutch lever free
play, turn the clutch lever free play
adjusting bolt in direction (a). To
decrease the clutch lever free
play, turn the adjusting bolt in di-
rection (b).
TIPIf the specified clutch lever free play
could be obtained as described above,
skip steps 4–7.4. Fully turn the adjusting bolt at theclutch lever in direction (a) to loos-
en the clutch cable.
5. Slide back the rubber cover that is located further down the clutch
cable, and then loosen the lock-
nut.
1. Locknut
2. Clutch lever free play adjusting bolt
3. Rubber cover
4. Clutch lever free playClutch lever free play:10.0–15.0 mm (0.39–0.59 in)
321
(a)(b)
4
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