Page 49 of 96
Periodic maintenance and adjustment
6-7
6
EAU18732
Removing and installing the
cowlings and panel
The cowlings and panel shown need to
be removed to perform some of the
maintenance jobs described in this
chapter. Refer to this section each time
a cowling or panel needs to be re-
moved and installed.
EAU55850
Cowling A
To remove the cowling
Remove the screws, and then take the
cowling off.To install the cowling
Place the cowling in the original posi-
tion, and then install the screws.
Cowling B
To remove the cowling
1. Remove cowling A and panel A.
2. Remove the screws, slide the
cowling forward, and then take it
off.
3. Disconnect the turn signal light
lead coupler.
To install the cowling
1. Connect the turn signal light lead
coupler.
1. Cowling A
2. Cowling B
3. Cowling C
4. Cowling D
5. Panel A
ZAUM1169
1. Screw
2. Cowling A
1. Screw
2. Cowling B
ZAUM1170
ZAUM1171
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Periodic maintenance and adjustment
6-8
62. Fit the projection on the cowling
into the slot, and then slide the
cowling backward.
3. Install the screws.
4. Install cowling A and panel A.
Cowling C
To remove the cowling
Remove the screws, and then pull the
cowling off as shown.
To install the cowling
Place the cowling in the original posi-
tion, and then install the screws.
Cowling D
To remove the cowling
1. Remove panel A, cowlings A, B
and C.
2. Remove the screws and the quick
fasteners, and then take the cowl-
ing off.
TIP
The quick fastener is removed by
pushing the center pin in with a screw-
driver, then pulling the fastener out.
To install the cowling
1. Place the cowling in the original
position, and then install the
screws and the quick fasteners.
TIP
To install the quick fasteners, push the
center pin out so that it will protrude
from the fastener head, insert the fas-
tener into the cowling, and then push
the protruding pin in until it is flush with
the fastener head.
2. Install cowlings C, B, A and panel
A.
EAUM2371Panel A
To remove the panel
1. Remove the rider seat. (See page
3-19.)
2. Remove the screws, and then take
the panel off.
1. Screw
2. Cowling C
ZAUM1465
1. Quick fastener
2. Screw
3. Cowling D
ZAUM1173
UBR6E0E0.book Page 8 Wednesday, August 17, 2016 1:26 PM
Page 51 of 96
Periodic maintenance and adjustment
6-9
6 To install the panel
1. Place the panel in the original po-
sition, and then install the screws.
2. Install the rider seat.
EAU19633
Checking the spark plug
The 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 plug
1. Remove cowling A. (See page
6-7.)
2. Remove the spark plug cap.
3. Remove the spark plug as shown,
with the spark plug wrench includ-
ed in the owner’s tool kit.
1. Screw
2. Panel A
1. Spark plug cap
1. Spark plug wrench
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Page 52 of 96

Periodic maintenance and adjustment
6-10
6To check the spark plug
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).
TIP
If 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 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 specifi-
cation.2. Clean the surface of the spark
plug gasket and its mating sur-
face, 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.
TIP
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
specified torque as soon as possible.
4. Install the spark plug cap.
5. Install the cowling.Specified spark plug:
NGK/CR9E
1. Spark plug gap
Spark 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, 9.04 ft·lbf)
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Page 53 of 96

Periodic maintenance and adjustment
6-11
6
EAUM3491
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. 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 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.
NOTICE: Do not operate the ve-
hicle until you know that the en-
gine oil level is sufficient.
[ECA10012]
TIP
The 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. Install the oil filler cap.
To change the engine oil (with or
without oil filter element replace-
ment)
1. Remove cowling D. (See page
6-7.)
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.
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
1
2
3
ZAUE1300
ZAUM1467
2
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Page 54 of 96

Periodic maintenance and adjustment
6-12
64. 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
engine oil strainer, to drain the oil
from the crankcase. NOTICE:
When removing the engine oil
drain bolt, the O-ring, compres-
sion spring, and oil strainer will
fall out. Take care not to lose
these parts.
[ECA11002]
6. Clean the engine oil strainer with
solvent.
TIP
Skip steps 7…9 if the oil filter element is
not 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 tight-
ening them to the specified
torque.
TIP
Make sure that the O-ring is properly
seated.
10. Install the engine oil strainer, com-
pression spring, O-ring and the
engine oil drain bolt, and then
tighten it to the specified torque.
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 torques:
Oil filter element cover bolt:
10 Nm (1.0 m·kgf, 7.2 ft·lbf)
UBR6E0E0.book Page 12 Wednesday, August 17, 2016 1:26 PM
Page 55 of 96
![YAMAHA YZF-R125 2017 Owners Manual Periodic maintenance and adjustment
6-13
6 NOTICE: Before installing the
engine oil drain bolt, do not for-
get to install the O-ring, com-
pression spring, and oil strainer
in position.
[ECA10422]
1 YAMAHA YZF-R125 2017 Owners Manual Periodic maintenance and adjustment
6-13
6 NOTICE: Before installing the
engine oil drain bolt, do not for-
get to install the O-ring, com-
pression spring, and oil strainer
in position.
[ECA10422]
1](/manual-img/51/54250/w960_54250-54.png)
Periodic maintenance and adjustment
6-13
6 NOTICE: Before installing the
engine oil drain bolt, do not for-
get to install the O-ring, com-
pression spring, and oil strainer
in position.
[ECA10422]
11. Refill with the specified amount of
the recommended engine oil, and
then install and tighten the oil filler
cap.
NOTICE
ECA11621
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,
immediately 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.
14. Reset the oil change indicator.
(See page 3-10.)
Tightening torques:
Engine oil drain bolt:
32 Nm (3.2 m·kgf, 23 ft·lbf)
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)
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Page 56 of 96

Periodic maintenance and adjustment
6-14
6
EAU20071
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.
EAU20095To check the coolant level
1. Place the vehicle on a level sur-
face and hold it in an upright posi-
tion.
TIP
The coolant level must be
checked on a cold engine since
the level varies with engine tem-
perature.
Make sure that the vehicle is posi-
tioned straight up when checking
the coolant level. A slight tilt to the
side can result in a false reading.
2. Check the coolant level in the
coolant reservoir.
TIP
The coolant should be between the
minimum and maximum level marks.
3. If the coolant is at or below the
minimum level mark, remove the
reservoir cap. WARNING! Re-
move only the coolant reservoir
cap. Never attempt to remove
the radiator cap when the en-
gine is hot.
[EWA15162]
4. Add coolant to the maximum level
mark, and then install the reservoir
cap. NOTICE: 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 anti-
freeze content of the coolant as
soon as possible, otherwise the
effectiveness of the coolant will
be reduced.
[ECA10473]
1. Coolant reservoir
2. Maximum level mark
3. Minimum level mark
ZAUM1175
1. Coolant reservoir cap
Coolant reservoir capacity (up to
the maximum level mark):
0.25 L (0.26 US qt, 0.22 Imp.qt)
ZAUM1176
UBR6E0E0.book Page 14 Wednesday, August 17, 2016 1:26 PM