2015 YAMAHA MT-125 check engine

PERIODIC MAINTENANCE AND ADJUSTMENT
6-10
6To install the spark plug
1. Clean the surface of the spark
plug gasket and its mating sur-
face, 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.
EAUM3490
Engine oil and 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 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]
TIPThe engine oil should be between the
minimum and maximum level marks.
Tightening torque:
Spark plug:
12.5 Nm (1.25 m·kgf, 9.04 ft·lbf)
1. Engine oil filler cap
1. Dipstick
2. Maximum level mark
3. Minimum level mark
1
2
3
ZAUE1300
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PERIODIC MAINTENANCE AND ADJUSTMENT
6-13
6 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.)
EAU20071
CoolantThe 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.
EAUM1726
To 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.TIPThe coolant should be between the
minimum and maximum level marks.
3. If the coolant is at or below the
minimum level mark, remove
cowling A (See page 6-8.), and
then open the reservoir cap.
WARNING! Remove only the
coolant reservoir cap. Never at-
tempt to remove the radiator
cap when the engine is hot.
[EWA15162]
4. Add coolant to the maximum level
mark, and then close 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.1. Coolant reservoir cap
2. Maximum level mark
3. Minimum level markZAUM1207
FULL
LOW
2
3
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PERIODIC MAINTENANCE AND ADJUSTMENT
6-14
6If 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]
5. Install the cowling.
EAU33032
Changing the coolant
The coolant must be changed at the in-
tervals specified in the periodic main-
tenance and lubrication chart. Have a
Yamaha dealer change the coolant.
WARNING! Never attempt to remove
the radiator cap when the engine is
hot.
[EWA10382]EAUM2391
Replacing the air filter ele-
ment and cleaning the check
hoseThe 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.
Coolant reservoir capacity (up to
the maximum level mark):
0.25 L (0.26 US qt, 0.22 Imp.qt)
1. Air filter check hose
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PERIODIC MAINTENANCE AND ADJUSTMENT
6-15
6
EAU44735
Checking the engine idling
speedCheck the engine idling speed and, if
necessary, have it corrected by a
Yamaha dealer.
EAU48433
Adjusting the throttle grip free
playThe throttle grip free play should mea-
sure 3.0–5.0 mm (0.12–0.20 in) at the
inner edge of the throttle grip. Periodi-
cally check the throttle grip free play
and, if necessary, adjust it as follows.TIPThe engine idling speed must be cor-
rectly adjusted before checking and
adjusting the throttle grip free play.1. Slide the rubber cover back.
2. Loosen the locknut.3. To increase the throttle grip free
play, turn the adjusting nut in di-
rection (a). To decrease the throt-
tle grip free play, turn the adjusting
nut in direction (b).
4. Tighten the locknut and then slide
the rubber cover to its original po-
sition.
Engine idling speed:
1350–1550 r/min
1. Throttle grip free play
1
1. Rubber cover
2. Adjusting nut
3. LocknutZAUM12081
23
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PERIODIC MAINTENANCE AND ADJUSTMENT
6-16
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.
EAUM2405
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 totalweight 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):
0–90 kg (0–198 lb):
Front:
180 kPa (1.80 kgf/cm², 26 psi)
Rear:
200 kPa (2.00 kgf/cm², 29 psi)
MT125 90–180 kg (198–397 lb)
MT125A 90–178 kg (198–392 lb):
Front:
180 kPa (1.80 kgf/cm², 26 psi)
Rear:
225 kPa (2.25 kgf/cm², 33 psi)
Maximum load*:
MT125 180 kg (397 lb)
MT125A 178 kg (392 lb)
* Total weight of rider, passenger, car-
go and accessories
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PERIODIC MAINTENANCE AND ADJUSTMENT
6-24
6
EAU22762
Drive chain slackThe drive chain slack should be
checked before each ride and adjusted
if necessary.
EAUM3550
To check the drive chain slack
1. Place the motorcycle on the side-
stand.TIPWhen checking and adjusting the drive
chain slack, there should be no weight
on the motorcycle.2. Shift the transmission into the
neutral position.
3. Measure the drive chain slack at
the arrow mark on the swingarm
as shown in the illustration.4. If the drive chain slack is incorrect,
adjust it as follows.
EAU34318
To adjust the drive chain slack
Consult a Yamaha dealer before ad-
justing the drive chain slack.
1. Loosen the axle nut and the lock-
nut on each side of the swingarm.2. To tighten the drive chain, turn the
drive chain slack adjusting bolt on
each side of the swingarm in di-
rection (a). To loosen the drive
chain, turn the adjusting bolt on
each side of the swingarm in di-
rection (b), and then push the rear
wheel forward. NOTICE: Improp-
er drive chain slack will over-
load the engine as well as other
vital parts of the motorcycle and
can lead to chain slippage or
breakage. To prevent this from
Drive chain slack:
35.0–45.0 mm (1.38–1.77 in)
1. Drive chain slackZAUM1233
1. Axle nut
2. Drive chain slack adjusting bolt
3. Locknut
4. Alignment marksZAUM1183
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PERIODIC MAINTENANCE AND ADJUSTMENT
6-29
6
EAU23284
Checking the steeringWorn or loose steering bearings may
cause danger. Therefore, the operation
of the steering must be checked as fol-
lows at the intervals specified in the
periodic maintenance and lubrication
chart.
1. Place a stand under the engine to
raise the front wheel off the
ground. (See page 6-36 for more
information.) WARNING! To
avoid injury, securely support
the vehicle so there is no danger
of it falling over.
[EWA10752]
2. Hold the lower ends of the front
fork legs and try to move them for-
ward and backward. If any free
play can be felt, have a Yamaha
dealer check or repair the steer-
ing.
EAU23292
Checking the wheel bearingsThe front and rear wheel bearings must
be checked at the intervals specified in
the periodic maintenance and lubrica-
tion chart. If there is play in the wheel
hub or if the wheel does not turn
smoothly, have a Yamaha dealer
check the wheel bearings.
ZAUM1213
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PERIODIC MAINTENANCE AND ADJUSTMENT
6-36
6
EAU24351
Supporting the motorcycleSince this model is not equipped with a
centerstand, follow these precautions
when removing the front and rear
wheel or performing other mainte-
nance requiring the motorcycle to
stand upright. Check that the motorcy-
cle is in a stable and level position be-
fore starting any maintenance. A
strong wooden box can be placed un-
der the engine for added stability.
To service the front wheel
1. Stabilize the rear of the motorcy-
cle by using a motorcycle stand
or, if an additional motorcycle
stand is not available, by placing a
jack under the frame in front of the
rear wheel.
2. Raise the front wheel off the
ground by using a motorcycle
stand.
To service the rear wheel
Raise the rear wheel off the ground by
using a motorcycle stand or, if a motor-
cycle stand is not available, by placinga jack either under each side of the
frame in front of the rear wheel or under
each side of the swingarm.
EAU44792
Front wheel (for non-ABS
models)
WARNING
EWA14841
For the ABS model, have a Yamaha
dealer remove and install the wheel.
EAU56531
To remove the front wheel
WARNING
EWA10822
To avoid injury, securely support the
vehicle so there is no danger of it
falling over.1. Loosen the front wheel axle pinch
bolts, then the wheel axle and the
brake caliper bolts.
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