YAMAHA YZF-R125 2008 Service Manual

PERIODIC MAINTENANCE AND MINOR REPAIR
6-9
6 2. Check the spark plug for electrode
erosion and excessive carbon or
other deposits, and replace it if
necessary.
To install the spark plug
1. Measure the spark plug gap with a
wire thickness gauge and, if nec-
essary, adjust the gap to specifica-
tion.2. Clean the surface of the spark plug
gasket and its mating surface, and
then wipe off any grime from the
spark plug threads.
3. Install the spark plug with the
spark plug wrench, and then tight-
en it to the specified torque.
NOTE:
If 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 speci-fied torque as soon as possible.
4. Install the spark plug cap.
5. Install the cowling.
EAUM2380
Engine oil and oil filter ele-
ment The 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 engine oil level
1. Place the vehicle on a level sur-
face and hold it in an upright posi-
tion.NOTE:
Make sure that the vehicle is positioned
straight up when checking the oil level.
A slight tilt to the side can result in afalse 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 oil filler cap, wipe
the dipstick clean, insert it back
into the oil filler hole (without
screwing it in), and then remove it
again to check the oil level.
Specified spark plug:
NGK/CR8E1. Spark plug gapSpark plug gap:
0.7–0.8 mm (0.028–0.031 in)
1
ZAUM0037
Tightening torque:
Spark plug:
12.5 Nm (1.25 m·kgf, 9.0 ft·lbf)
U5D7E0E0.book Page 9 Tuesday, December 18, 2007 10:13 AM

PERIODIC MAINTENANCE AND MINOR REPAIR
6-10
6
NOTE:The engine oil should be between theminimum and maximum level marks.
CAUTION:
ECA10010
Do not operate the vehicle until you
know that the engine oil level is suf-ficient.
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. Install the oil filler cap.
To change the engine oil (with or
without oil filter element replace-
ment)
1. Remove cowling D. (See page
6-6.)
2. Start the engine, warm it up for
several minutes, and then turn it
off.
3. Install the engine oil drain attach-
ment, provided with the owner’s
tool kit, under the drain bolt of the
crankcase.4. Place an oil pan under the engine
to collect the used oil.
5. Remove the engine oil filler cap
and the drain bolt along with the O-
ring, compression spring, and en-
gine oil strainer, to drain the oil
from the crankcase.
1. Engine oil filler cap
1. Dipstick
2. Maximum level mark
3. Minimum level mark
1. Engine oil drain bolt (crankcase)
2. Engine oil drain attachment
U5D7E0E0.book Page 10 Tuesday, December 18, 2007 10:13 AM

PERIODIC MAINTENANCE AND MINOR REPAIR
6-11
6
CAUTION:
ECA11000
When removing the engine oil drain
bolt, the O-ring, compression
spring, and oil strainer will fall out.Take care not to lose these parts.
6. Clean the engine oil strainer with
solvent.NOTE:Skip steps 7–9 if the oil filter element isnot being replaced.
7. Remove the oil filter element cover
by removing the bolts.8. Remove and replace the oil filter
element and O-ring.
9. Install the oil filter element cover by
installing the bolts, then tightening
them to the specified torque.
NOTE:
Make sure that the O-ring is properlyseated.
10. Install the engine oil strainer, com-
pression spring, O-ring and the en-
gine oil drain bolt, and then tighten
it to the specified torque.CAUTION:
ECA10420
Before installing the engine oil drain
bolt, do not forget to install the O-
ring, compression spring, and oilstrainer in position.
11. Add the specified amount of the
recommended engine oil, and then
install and tighten the oil filler cap.
1. Engine oil drain bolt
2. O-ring
3. Compression spring
4. Strainer
5. Oil pan
1. Bolt
2. Oil filter element cover
1. Oil filter element
2. O-ring
Tightening torque:
Oil filter element cover bolt:
10 Nm (1.0 m·kgf, 7.2 ft·lbf)
Tightening torque:
Engine oil drain bolt:
32 Nm (3.2 m·kgf, 23 ft·lbf)
U5D7E0E0.book Page 11 Tuesday, December 18, 2007 10:13 AM

PERIODIC MAINTENANCE AND MINOR REPAIR
6-12
6
CAUTION:
ECA11620


In order to prevent clutch slip-
page (since the engine oil also
lubricates the clutch), do not
mix any chemical additives. Do
not use oils with a diesel speci-
fication of “CD” or oils of a high-
er quality than specified. In
addition, do not use oils labeled
“ENERGY CONSERVING II” or
higher.


Make sure that no foreign mate-rial enters the crankcase.
12. Start the engine, and then let it idle
for several minutes while checking
it for oil leakage. If oil is leaking, im-
mediately turn the engine off and
check for the cause.13. Turn the engine off, and then
check the oil level and correct it if
necessary.
EAU20070
Coolant The coolant level should be checked
before each ride. In addition, the cool-
ant must be changed at the intervals
specified in the periodic maintenance
and lubrication chart.
EAU20091
To check the coolant level
1. Place the vehicle on a level sur-
face and hold it in an upright posi-
tion.NOTE:

The coolant level must be checked
on a cold engine since the level
varies with engine temperature.


Make sure that the vehicle is posi-
tioned straight up when checking
the coolant level. A slight tilt to theside can result in a false reading.
2. Check the coolant level in the cool-
ant reservoir.
NOTE:The coolant should be between theminimum and maximum level marks.
Recommended engine oil:
See page 8-1.
Oil quantity:
Without oil filter element replace-
ment:
0.95 L (1.00 US qt) (0.84 Imp.qt)
With oil filter element replacement:
1.00 L (1.06 US qt) (0.88 Imp.qt)
U5D7E0E0.book Page 12 Tuesday, December 18, 2007 10:13 AM

PERIODIC MAINTENANCE AND MINOR REPAIR
6-13
6 3. If the coolant is at or below the
minimum level mark, remove the
reservoir cap.4. Add coolant to the maximum level
mark, and then install the reservoir
cap.
CAUTION:
ECA10471


If coolant is not available, use
distilled water or soft tap water
instead. Do not use hard water
or salt water since it is harmful
to the engine.


If water has been used instead
of coolant, replace it with cool-
ant as soon as possible, other-
wise the cooling system will not
be protected against frost and
corrosion.


If water has been added to the
coolant, have a Yamaha dealer
check the antifreeze content of
the coolant as soon as possible,
otherwise the effectiveness ofthe coolant will be reduced.
WARNING
EWA10380
Never attempt to remove the radiatorcap when the engine is hot.NOTE:

The radiator fan is automatically
switched on or off according to the
coolant temperature in the radia-
tor.


If the engine overheats, see page6-37 for further instructions.
EAU33030
Changing the coolant
WARNING
EWA10380
Never attempt to remove the radiatorcap when the engine is hot.
The coolant must be changed at the in-
tervals specified in the periodic mainte-
nance and lubrication chart. Have a
Yamaha dealer change the coolant.
1. Coolant reservoir
2. Maximum level mark
3. Minimum level mark
1. Coolant reservoir cap
Coolant reservoir capacity (up to the
maximum level mark):
0.25 L (0.26 US qt) (0.22 Imp.qt)
U5D7E0E0.book Page 13 Tuesday, December 18, 2007 10:13 AM

PERIODIC MAINTENANCE AND MINOR REPAIR
6-14
6
EAUM2390
Replacing the air filter element
and cleaning the check hose The air filter element should be re-
placed at the intervals specified in the
periodic maintenance and lubrication
chart. Have a Yamaha dealer replace
the air filter element more frequently 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 check hose
1. Check the hose on the side of the
air filter case for accumulated dirt
or water.2. If dirt or water is visible, remove
the hose, clean it, and then install
it.
EAU33482
Adjusting the engine idling
speed The 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.
1. Remove panel A. (See page 6-6.)
2. Check the engine idling speed
and, if necessary, adjust it to spec-
ification by turning the idle adjust-
ing screw. To increase the engine
idling speed, turn the screw in di-
rection (a). To decrease the en-
gine idling speed, turn the screw in
direction (b).
1. Air filter check hoseU5D7E0E0.book Page 14 Tuesday, December 18, 2007 10:13 AM

PERIODIC MAINTENANCE AND MINOR REPAIR
6-15
6
NOTE:
If the specified idling speed cannot be
obtained as described above, have aYamaha dealer make the adjustment.
3. Install the panel.
EAU21370
Adjusting the throttle cable
free play The throttle cable free play should mea-
sure 3.0–5.0 mm (0.12–0.20 in) at the
throttle grip. Periodically check the
throttle cable free play and, if neces-
sary, adjust it as follows.NOTE:The engine idling speed must be cor-
rectly adjusted before checking and ad-justing the throttle cable free play.
1. Loosen the locknut.2. To increase the throttle cable free
play, turn the adjusting nut in direc-
tion (a). To decrease the throttle
cable free play, turn the adjusting
nut in direction (b).
3. Tighten the locknut.
1. Idle adjusting screwEngine idling speed:
1300–1500 r/min
1. Throttle cable free play
1. Locknut
2. Adjusting nut
U5D7E0E0.book Page 15 Tuesday, December 18, 2007 10:13 AM

PERIODIC MAINTENANCE AND MINOR REPAIR
6-16
6
EAU21401
Valve clearance The 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.
EAUM2400
Tires To maximize the performance, durabil-
ity, and safe operation of your motor-
cycle, note the following points
regarding the specified tires.
Tire air pressure
The tire air pressure should be checked
and, if necessary, adjusted before each
ride.
WARNING
EWA10500


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 ad-
justed in accordance with the
riding speed and with the total
weight of rider, passenger, car-
go, and accessories approvedfor this model.
WARNING
EWA11200
Because loading has an enormous
impact on the handling, braking,
performance and safety characteris-
tics of your vehicle, you should keep
the following precautions in mind.

NEVER OVERLOAD THE VEHI-
CLE! Operation of an overload-
ed vehicle may result in tire
damage, loss of control, or se-
vere injury. Make sure that the
total weight of rider, passenger,Tire air pressure (measured on cold
tires):
0–90 kg (0–198 lb):
Front:
175 kPa (25 psi) (1.75 kgf/cm²)
Rear:
200 kPa (29 psi) (2.00 kgf/cm²)
90–185 kg (198–408 lb):
Front:
175 kPa (25 psi) (1.75 kgf/cm²)
Rear:
225 kPa (33 psi) (2.25 kgf/cm²)
Maximum load*:
185 kg (408 lb)
* Total weight of rider, passenger, car-
go and accessories
U5D7E0E0.book Page 16 Tuesday, December 18, 2007 10:13 AM

PERIODIC MAINTENANCE AND MINOR REPAIR
6-17
6 cargo, and accessories does
not exceed the specified maxi-
mum load for the vehicle.


Do not carry along loosely
packed items, which can shift
during a ride.


Securely pack the heaviest
items close to the center of the
vehicle and distribute the
weight evenly on both sides.


Adjust the tire air pressure with
regard to the load.


Check the tire condition and airpressure before each ride.
Tire inspectionThe 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 sidewall is
cracked, have a Yamaha dealer re-
place the tire immediately.
NOTE:
The tire tread depth limits may differ
from country to country. Always complywith the local regulations.
WARNING
EWA10470


Have a Yamaha dealer replace
excessively worn tires. Besides
being illegal, operating the vehi-
cle with excessively worn tires
decreases riding stability and
can lead to loss of control.


The replacement of all wheel
and brake related parts, includ-
ing the tires, should be left to aYamaha dealer, who has the
necessary professional knowl-
edge and experience.
Tire information
This motorcycle is equipped with cast
wheels and tubeless tires with valves.WARNING
EWA10900


The front and rear tires should
be of the same make and de-
sign, otherwise the handling
characteristics of the motor-
cycle cannot be guaranteed.
1. Tire sidewall
2. Tire tread depth
Minimum tire tread depth (front and
rear):
1.6 mm (0.06 in)
1. Tire air valve
2. Tire air valve core
3. Tire air valve cap with seal
123
U5D7E0E0.book Page 17 Tuesday, December 18, 2007 10:13 AM

PERIODIC MAINTENANCE AND MINOR REPAIR
6-18
6


After extensive tests, only the
tires listed below have been ap-
proved for this model by
Yamaha Motor Co., Ltd.


Always make sure that the valve
caps are securely installed to
prevent air pressure leakage.


Use only the tire valves and
valve cores listed below toavoid tire deflation during a ride.
WARNING
EWA10600
This motorcycle is fitted with super-
high-speed tires. Note the following
points in order to make the most ef-
ficient use of these tires.

Use only the specified replace-
ment tires. Other tires may run
the danger of bursting at super
high speeds.


Brand-new tires can have a rela-
tively poor grip on certain road
surfaces until they have been
“broken in”. Therefore, it is ad-
visable before doing any high-
speed riding to ride conserva-
tively for approximately 100 km
(60 mi) after installing a new tire.


The tires must be warmed up
before a high-speed run.


Always adjust the tire air pres-
sure according to the operatingconditions.
EAU21960
Cast wheels To 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 or warpage be-
fore each ride. If any damage is
found, have a Yamaha dealer re-
place the wheel. Do not attempt
even the smallest repair to the
wheel. A deformed 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.


Ride at moderate speeds after
changing a tire since the tire sur-
face must first be “broken in” for it
to develop its optimal characteris-
tics.
Front tire:
Size:
100/80-17 M/C 52H
Manufacturer/model:
PIRELLI/SPORT DEMON
MICHELIN/PILOT SPORTY
Tire air valve:
TR412
Va l ve c o r e :
V3002 (original)
Rear tire:
Size:
130/70-17 M/C 62H
Manufacturer/model:
PIRELLI/SPORT DEMON
MICHELIN/PILOT SPORTY
Tire air valve:
TR412
Va l ve c o r e :
V3002 (original)
U5D7E0E0.book Page 18 Tuesday, December 18, 2007 10:13 AM