check engine YAMAHA MT-125 2015 User Guide

FOR YOUR SAFETY – PRE-OPERATION CHECKS
4-1
4
EAU15598
Inspect your vehicle each time you use it to make sure the vehicle is in safe operating condition. Always follow the inspection
and maintenance procedures and schedules described in the Owner’s Manual.
WARNING
EWA11152
Failure to inspect or maintain the vehicle properly increases the possibility of an accident or equipment damage.
Do not operate the vehicle if you find any problem. If a problem cannot be corrected by the procedures provided in
this manual, have the vehicle inspected by a Yamaha dealer.Before using this vehicle, check the following points:
ITEM CHECKS PAGE
Fuel• Check fuel level in fuel tank.
• Refuel if necessary.
• Check fuel line for leakage.3-16
Engine oil• Check oil level in engine.
• If necessary, add recommended oil to specified level.
• Check vehicle for oil leakage.6-10
Coolant• Check coolant level in reservoir.
• If necessary, add recommended coolant to specified level.
• Check cooling system for leakage.6-13
Front brake• Check operation.
• If soft or spongy, have Yamaha dealer bleed hydraulic system.
• Check brake pads for wear.
• Replace if necessary.
• Check fluid level in reservoir.
• If necessary, add specified brake fluid to specified level.
• Check hydraulic system for leakage.6-21, 6-22
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OPERATION AND IMPORTANT RIDING POINTS
5-2
5
NOTICE
ECA11834
If a warning or indicator light does
not come on initially when the key is
turned to “ON”, or if a warning or in-
dicator light remains on, see page
3-2 for the corresponding warning
and indicator light circuit check.
For ABS models:The ABS warning light should
come on when the key is turned to
“ON”, and then go off after travel-
ing at a speed of 10 km/h (6 mi/h)
or higher.
NOTICE
ECA17682
If the ABS warning light does not
come on and then go off as ex-
plained above, see page 3-2 for the
warning light circuit check.2. Shift the transmission into the
neutral position. The neutral indi-
cator light should come on. If not,
ask a Yamaha dealer to check the
electrical circuit.
3. Start the engine by pushing the
start switch.If the engine fails to start, release
the start switch, wait a few sec-
onds, and then try again. Each
starting attempt should be as
short as possible to preserve the
battery. Do not crank the engine
more than 10 seconds on any one
attempt.
NOTICE
ECA11043
For maximum engine life, never ac-
celerate hard when the engine is
cold!
EAU16673
ShiftingShifting gears lets you control the
amount of engine power available for
starting off, accelerating, climbing hills,
etc.
The gear positions are shown in the il-
lustration.TIPTo shift the transmission into the neu-
tral position, press the shift pedal down
repeatedly until it reaches the end of its
travel, and then slightly raise it.1. Shift pedal
2. Neutral positionZAUM1203
1 N2 3 4 5
6
1
2
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OPERATION AND IMPORTANT RIDING POINTS
5-4
5500–1000 km (300–600 mi)
Avoid prolonged operation above 8000
r/min.
Rev the engine freely through the
gears, but do not use full throttle at any
time. NOTICE: After 1000 km (600 mi)
of operation, the engine oil must be
changed, the oil filter cartridge or el-
ement replaced, and the oil strainer
cleaned.
[ECA10322]
1000 km (600 mi) and beyond
The vehicle can now be operated nor-
mally.NOTICE
ECA10311
Keep the engine speed out of
the tachometer red zone.
If any engine trouble should oc-
cur during the engine break-in
period, immediately have a
Yamaha dealer check the vehi-
cle.
EAU17214
ParkingWhen parking, stop the engine, and
then remove the key from the main
switch.
WARNING
EWA10312
Since the engine and exhaust
system can become very hot,
park in a place where pedestri-
ans or children are not likely to
touch them and be burned.
Do not park on a slope or on soft
ground, otherwise the vehicle
may overturn, increasing the
risk of a fuel leak and fire.
Do not park near grass or other
flammable materials which
might catch fire.
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PERIODIC MAINTENANCE AND ADJUSTMENT
6-3
6
EAU46872
TIPThe annual checks must be performed every year, except if a kilometer-based maintenance, or for the UK, a
mileage-based maintenance, is performed instead.
From 30000 km (17500 mi), repeat the maintenance intervals starting from 6000 km (3500 mi).
Items marked with an asterisk should be performed by a Yamaha dealer as they require special tools, data and tech-
nical skills.
EAU46921
Periodic maintenance chart for the emission control systemNO. ITEM CHECK OR MAINTENANCE JOBODOMETER READING
ANNUAL
CHECK 1000 km
(600 mi)6000 km
(3500 mi)12000 km
(7000 mi)18000 km
(10500 mi)24000 km
(14000 mi)
1*Fuel line• Check fuel hoses for cracks or
damage.√√√√√
2 Spark plug• Check condition.
• Clean and regap.√√
•Replace.√√
3*Valves• Check valve clearance.
•Adjust.√√√√
4*Fuel injection• Check engine idle speed.√√√√√
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PERIODIC MAINTENANCE AND ADJUSTMENT
6-6
6
19 Sidestand• Check operation.
• Lubricate with lithium-soap-
based grease.√√√√√
20*Sidestand switch• Check operation.√√√√√√
21*Front fork• Check operation and for oil leak-
age.√√√√
22*Shock absorber as-
sembly• Check operation and shock ab-
sorber for oil leakage.√√√√
23*Rear suspension re-
lay arm and con-
necting arm
pivoting points• Check operation.√√√√
• Lubricate with lithium-soap-
based grease.√√
24 Engine oil• Change. (See pages 3-10 and
6-10.)√When the oil change indicator light flashes (2000 km (1200 mi) af-
ter the initial 1000 km [600 mi] and every 3000 km (1800 mi)
thereafter)
• Check oil level and vehicle for oil
leakage.Every 3000 km (1800 mi)√
25Engine oil filter ele-
ment• Replace.√√√√√
26*Cooling system• Check coolant level and vehicle
for coolant leakage.√√√√√
• Change coolant. Every 3 years
27*Front and rear
brake switches• Check operation.√√√√√√
28Moving parts and
cables• Lubricate.√√√√√ NO. ITEM CHECK OR MAINTENANCE JOBODOMETER READING
ANNUAL
CHECK 1000 km
(600 mi)6000 km
(3500 mi)12000 km
(7000 mi)18000 km
(10500 mi)24000 km
(14000 mi)U5D7E4E0.book Page 6 Thursday, July 10, 2014 3:01 PM

PERIODIC MAINTENANCE AND ADJUSTMENT
6-9
6
EAU19605
Checking the spark plugThe 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 the spark plug cap.
2. Remove the spark plug as shown,
with the spark plug wrench includ-
ed in the owner’s tool kit.To 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).
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 electrode
erosion 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.
1. Spark plug cap
1. Spark plug wrench
Specified spark plug:
NGK/CR9E
1. Spark plug gap
Spark plug gap:
0.7–0.8 mm (0.028–0.031 in)
1
ZAUM0037
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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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