YAMAHA YBR125 2014 Service Manual

PERIODIC MAINTENANCE AND ADJUSTMENT
6-8
6
Panel B
To remove the panel
1. Slide the panel lock cover open,
insert the key into the lock, and
then turn it 1/4 turn clockwise.
2. Pull the front of the panel out with the key inserted in the lock, and
then slide the panel forward to re-
lease it in the rear. To install the panel
1. Secure the rear of the panel, and
then push the front of the panel in
with the key inserted in the lock.
2. While pushing the panel inward, turn the key counterclockwise to
the original position, remove it,
and then close the panel lock cov-
er.
EAU19605
Checkin g the spark plu gThe 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 the spark plug cap.
2. Remove the spark plug as shown, with the spark plug wrench includ-
ed in the owner’s tool kit.
1. Panel lock cover
2. Unlock.
1
2
1. Spark plug cap
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PERIODIC MAINTENANCE AND ADJUSTMENT
6-9
6To 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. 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.
1. Spark plug wrench
Specifie d spark plu g:
NGK/CR6HSA1. Spark plug gapSpark plu g g ap:
0.6–0.7 mm (0.024–0.028 in)
Ti ghtenin g torque:
Spark plug: 13 Nm (1.3 m·kgf, 9.4 ft·lbf)
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PERIODIC MAINTENANCE AND ADJUSTMENT
6-10
6
EAU37175
Engine oilThe engine oil level should be checked
before each ride. In addition, the oil
must be changed at the intervals spec-
ified in the periodic maintenance and
lubrication 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 engine oil dipstick
clean, insert it back into the oil fill-
er hole (without screwing it in), and
then remove it again to check the
oil level.
TIPThe engine oil should be between the
minimum and maximum level marks.
4. If the engine oil is at or below theminimum level mark, add suffi-
cient oil of the recommended type
to raise it to the correct level.
5. Insert the dipstick into the oil filler hole, and then tighten the oil filler
cap.
To chan ge the en gine oil
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.
1. Engine oil filler cap
1. Engine oil dipstick
2. Maximum level mark
3. Minimum level mark
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PERIODIC MAINTENANCE AND ADJUSTMENT
6-11
64. Install the engine oil drain bolt and
its new gasket, and then tighten
the bolt to the specified torque.
5. Refill with the specified amount of the recommended engine oil, and
then install and tighten the oil filler
cap.
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.6. 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.
7. Turn the engine off, wait a few mi- nutes until the oil settles, and then
check the oil level and correct it if
necessary.
EAU37124
Cleanin g the air filter elementThe air filter element should be cleaned
at the intervals specified in the periodic
maintenance and lubrication chart.
Clean or, if necessary, replace the air
filter element more frequently if you are
riding in unusually wet or dusty areas.
1. Remove panel A. (See page 6-7.)
2. Remove the air filter case cover by removing the screws.
3. Remove the air filter element.
1. Engine oil drain bolt
2. Gasket
3. Oil panTi ghtenin g torque:
Engine oil drain bolt:
20 Nm (2.0 m·kgf, 14 ft·lbf)
Recommended engine oil: See page 8-1.
Oil change quantity: 1.00 L (1.06 US qt, 0.88 Imp.qt)3
2
1
1. Screw
2. Air filter case cover
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PERIODIC MAINTENANCE AND ADJUSTMENT
6-12
6
4. Remove the sponge material from
the air filter element.
5. Lightly tap the air filter element to remove most of the dust and dirt,
and then blow the remaining dirt
out with compressed air on the
mesh side as shown. If the air filter
element is damaged, replace it. 6. Clean the sponge material with
solvent, then squeeze the remain-
ing solvent out, and be sure to let
the sponge material dry before in-
stalling it into the air filter element.
If the sponge material is damaged,
replace it. WARNING! Use only a
d ed icated parts cleanin g sol-
vent. To avoi d the risk of fire or
explosion, do not use gasoline
or solvents with a low flash
point.
[EWA10432]
NOTICE: To avoi d
d amag ing the spon ge material,
han dle it g ently an d carefully,
an d d o not twist it.
[ECA15102]
7. Install the sponge material into the
air filter element, and then install
the air filter element into the air fil-
ter case. NOTICE: Make sure
that the air filter element is
properly seated in the air filter
case. The en gine shoul d never
b e operated without the air filter
element installed , otherwise the
piston(s) an d/or cylin der(s) may
b ecome excessively worn.
[ECA10482]
8. Install the air filter case cover by
installing the screws.
9. Check the hose at the bottom of the air filter case for accumulated
dust or water, and if necessary,
drain it by removing the clamp,
and then removing the plug.
1. Sponge material
2. Air filter element
1. Air filter element
1
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PERIODIC MAINTENANCE AND ADJUSTMENT
6-13
610. Install the plug into the check
hose, and then install the clamp.
11. Install the panel.
EAU44735
Checkin g the eng ine idlin g
spee dCheck the engine idling speed and, if
necessary, have it corrected by a
Yamaha dealer.
EAU21385
Checkin g the throttle grip free
playThe throttle grip free play should mea-
sure 3.0–7.0 mm (0.12–0.28 in) at the
inner edge of the throttle grip. Periodi-
cally check the throttle grip free play
and, if necessary, have a Yamaha deal-
er adjust it.
1. Clamp
2. Air filter check hose plug
En gine i dlin g spee d:
1300–1500 r/min
1. Throttle grip free play
1
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PERIODIC MAINTENANCE AND ADJUSTMENT
6-14
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.
EAU21568
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 b e
checked and a djuste d on col d
tires (i.e., when the temperature
of the tires equals the am bient
temperature).
 The tire air pressure must b e
a d juste d in accor dance with the
ri din g speed and with the total wei
ght of ri der, passen ger, car-
g o, an d accessories approve d
for this mo del.
WARNING
EWA10512
Never overloa d your vehicle. Opera-
tion of an overloa ded vehicle coul d
cause an acci dent.
Tire air pressure (measure d on col d
tires): Up to 90 k g (198 l b) loa d:
Front:
175 kPa (1.75 kgf/cm², 25 psi)
Rear: 200 kPa (2.00 kgf/cm², 29 psi)
90 k g (198 l b) to maximum loa d:
Front: 175 kPa (1.75 kgf/cm², 25 psi)
Rear: 280 kPa (2.80 kgf/cm², 41 psi)
Maximum loa d*:
194 kg (428 lb)
* Total weight of rider, passenger, car- go and accessories
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PERIODIC MAINTENANCE AND ADJUSTMENT
6-15
6Tire 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.
Tire information
This motorcycle is equipped with tube-
less tires, tire air valves and cast
wheels.
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 b e 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 Motor Co., Ltd.
WARNING
EWA10472
 Have a Yamaha dealer replace
excessively worn tires. Besi des
b ein g ille gal, operatin g the vehi-
cle with excessively worn tires
d ecreases rid ing sta bility an d
can lead 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 dge an d experience to do so.
 Ride at mo derate speed s after
chan gin g a tire since the tire
surface must first be “ broken
in” for it to develop its optimal
characteristics.
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:
2.75-18 42P
Manufacturer/model:
CHENG SHIN/C-910
Rear tire: Size:
90/90-18 57P
Manufacturer/model: CHENG SHIN/C-905
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PERIODIC MAINTENANCE AND ADJUSTMENT
6-16
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.
EAUP0131
Adjustin g the clutch lever free
playThe clutch lever free play should mea-
sure 10.0–15.0 mm (0.39–0.59 in) as
shown. Periodically check the clutch
lever free play and, if necessary, adjust
it as follows.
1. Slide the rubber cover back 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 the
clutch lever in direction (a) to loos-
en the clutch cable.
5. Loosen the clutch cable locknut, located towards the center of the
cable.
6. To increase the clutch lever free play, turn the clutch lever free play
adjusting nut in direction (a). To
1. Rubber cover
2. Locknut
3. Clutch lever free play adjusting bolt
4. Clutch lever free play4 123
1. Locknut
2. Clutch lever free play adjusting nut
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PERIODIC MAINTENANCE AND ADJUSTMENT
6-17
6decrease the clutch lever free
play, turn the adjusting nut in di-
rection (b).
7. Tighten the locknut at the clutch cable.
8. Tighten the locknut at the clutch lever, and then slide the rubber
cover to its original position.
EAU37914
Checkin g the brake lever free
playThere should be no free play at the
brake lever end. If there is free play,
have a Yamaha dealer inspect the
brake system.
WARNING
EWA14212
A soft or spon gy feelin g in the b rake
lever can in dicate the presence of
air in the hy draulic system. If there is
air in the hy draulic system, have a
Yamaha dealer blee d the system be-
fore operatin g the vehicle. Air in the
hy draulic system will diminish the b
rakin g performance, which may re-
sult in loss of control an d an acci-
d ent.1. No brake lever free play
1
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