2015 YAMAHA MT-125 check engine light

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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10-1
10
INDEX
AABS (for ABS models) .......................... 3-14
ABS warning light (for ABS models) ....... 3-3
Air filter element and check hose,
replacing and cleaning ....................... 6-14
Auxiliary light ........................................ 6-34BBattery .................................................. 6-30
Brake and clutch levers, checking and
lubricating........................................... 6-26
Brake fluid, changing............................ 6-23
Brake fluid level, checking.................... 6-22
Brake lever............................................ 3-13
Brake light switches ............................. 6-21
Brake pedal .......................................... 3-14
Brake pedal, checking and
lubricating........................................... 6-27
Brake pedal free play, adjusting ........... 6-20CCables, checking and lubricating ......... 6-26
Care ........................................................ 7-1
Catalytic converter ............................... 3-17
Clutch lever........................................... 3-13
Clutch lever free play, adjusting ........... 6-19
Coolant ................................................. 6-13
Cowlings, removing and installing.......... 6-8DDimmer switch...................................... 3-12
Drive chain, cleaning and lubricating ... 6-25
Drive chain slack .................................. 6-24EEngine break-in ...................................... 5-3
Engine idling speed, checking.............. 6-15
Engine oil and oil filter element............. 6-10Engine stop switch............................... 3-12
Engine trouble warning light .................. 3-3
FFront and rear brake pads, checking ... 6-21
Front brake lever free play, checking ... 6-20
Front fork, checking ............................. 6-28
Fuel ...................................................... 3-16
Fuel consumption, tips for reducing ...... 5-3
Fuel level warning light........................... 3-2
Fuel tank cap........................................ 3-15
Fuses, replacing ................................... 6-31HHandlebar switches ............................. 3-11
Headlight bulb, replacing ..................... 6-33
High beam indicator light ....................... 3-2
Horn switch .......................................... 3-12IIdentification numbers ........................... 9-1
Ignition circuit cut-off system .............. 3-19
Indicator lights and warning lights ......... 3-2
Info switch ............................................ 3-12LLicense plate light bulb, replacing ....... 6-35MMain switch/steering lock ...................... 3-1
Maintenance and lubrication, periodic... 6-4
Maintenance, emission control
system ................................................. 6-3
Matte color, caution ............................... 7-1
Model label............................................. 9-1
Multi-function meter unit ........................ 3-4NNeutral indicator light ............................. 3-2
PParking.................................................... 5-4
Part locations.......................................... 2-1
Pass switch........................................... 3-12RRider seat.............................................. 3-18SSafety information................................... 1-1
Shifting.................................................... 5-2
Shift pedal............................................. 3-13
Sidestand.............................................. 3-18
Sidestand, checking and lubricating .... 6-27
Spark plug, checking .............................. 6-9
Specifications ......................................... 8-1
Starting the engine ................................. 5-1
Start switch ........................................... 3-12
Steering, checking ................................ 6-29
Storage ................................................... 7-3
Supporting the motorcycle ................... 6-36
Swingarm pivots, lubricating ................ 6-28TTail/brake light ...................................... 6-34
Throttle grip and cable, checking and
lubricating ........................................... 6-26
Throttle grip free play, adjusting ........... 6-15
Tires ...................................................... 6-16
Tool kit .................................................... 6-2
Troubleshooting .................................... 6-40
Troubleshooting charts ......................... 6-41
Turn signal indicator light ....................... 3-2
Turn signal light bulb, replacing............ 6-35
Turn signal switch ................................. 3-12VValve clearance..................................... 6-16
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