2016 YAMAHA MT-25 engine

Operation and important riding points
5-4
5
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
6-1
6
EAU17246
Periodic inspection, adjustment, and
lubrication will keep your vehicle in the
safest and most efficient condition
possible. Safety is an obligation of the
vehicle owner/operator. The most im-
portant points of vehicle inspection,
adjustment, and lubrication are ex-
plained on the following pages.
The intervals given in the periodic
maintenance charts should be simply
considered as a general guide under
normal riding conditions. However, de-
pending on the weather, terrain, geo-
graphical location, and individual use,
the maintenance intervals may need to
be shortened.
WARNING
EWA10322
Failure to properly maintain the vehi-
cle or performing maintenance ac-
tivities incorrectly may increase
your risk of injury or death during
service or while using the vehicle. If
you are not familiar with vehicle ser-
vice, have a Yamaha dealer perform
service.
WARNING
EWA15123
Turn off the engine when performing
maintenance unless otherwise
specified.
A running engine has moving
parts that can catch on body
parts or clothing and electrical
parts that can cause shocks or
fires.
Running the engine while ser-
vicing can lead to eye injury,
burns, fire, or carbon monoxide
poisoning – possibly leading to
death. See page 1-3 for more in-
formation about carbon monox-
ide.
WARNING
EWA15461
Brake discs, calipers, drums, and
linings can become very hot during
use. To avoid possible burns, let
brake components cool before
touching them.
EAUB1402
Owner’s tool kitThe owner’s tool kit is located on the
bottom of the passenger seat (see
page 3-16) and is held in place with an
O-ring.
The service information included in this
manual and the tools provided in the
owner’s tool kit are intended to assist
you in the performance of preventive
maintenance and minor repairs. How-
ever, additional tools such as a torque
wrench may be necessary to perform
certain maintenance work correctly.1. Owner’s tool kit
2. O-ring
1
2
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Periodic maintenance and adjustment
6-6
6
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 Engine oil• Change. (See pages 3-4 and 6-9.)√When the oil change indicator flashes
• Check oil level and vehicle for oil
leakage.Every 5000 km (3000 mi)√
24Engine oil filter car-
tridge•Replace.√√√
25*Cooling system• Check coolant level and vehicle
for coolant leakage.√√√√√
• Change coolant. Every 3 years
26*Front and rear
brake switches• Check operation.√√√√√√
27Moving parts and
cables• Lubricate.√√√√√
28*Throttle grip• Check operation.
• Check throttle grip free play, and
adjust if necessary.
• Lubricate cable and grip housing.√√√√√
29*Lights, signals and
switches• Check operation.
• Adjust headlight beam.√√√√√√ NO. ITEM CHECK OR MAINTENANCE JOBODOMETER READING
ANNUAL
CHECK 1000 km
(600 mi)10000 km
(6000 mi)20000 km
(12000 mi)30000 km
(18000 mi)40000 km
(24000 mi)
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Periodic maintenance and adjustment
6-8
6
EAU19643
Checking the spark plugsThe spark plugs are important engine
components, which should be
checked periodically, preferably by a
Yamaha dealer. Since heat and depos-
its will cause any spark plug to slowly
erode, they should be removed and
checked in accordance with the peri-
odic maintenance and lubrication
chart. In addition, the condition of the
spark plugs can reveal the condition of
the engine.
The porcelain insulator around the
center electrode of each spark plug
should be a medium-to-light tan (the
ideal color when the vehicle is ridden
normally), and all spark plugs installed
in the engine should have the same
color. If any spark plug shows a dis-
tinctly different color, the engine could
be operating improperly. Do not at-
tempt to diagnose such problems
yourself. Instead, have a Yamaha deal-
er check the vehicle.
If a spark plug shows signs of elec-
trode erosion and excessive carbon or
other deposits, it should be replaced.Before installing a spark plug, the
spark plug gap should be measured
with a wire thickness gauge and, if
necessary, adjusted to specification.
Clean the surface of the spark plug
gasket and its mating surface, and
then wipe off any grime from the spark
plug threads.
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.
Specified spark plug:
NGK/CR9E
1. Spark plug gap
Spark plug gap:
0.7–0.8 mm (0.028–0.031 in)
Tightening torque:
Spark plug:
13 Nm (1.3 m·kgf, 9.4 ft·lbf)
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Periodic maintenance and adjustment
6-9
6
EAUN1150
Engine oil and oil filter car-
tridgeThe engine oil level should be checked
before each ride. In addition, the oil
must be changed and the oil filter car-
tridge replaced at the intervals speci-
fied in the periodic maintenance and
lubrication 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, and then check the oil level
through the engine oil level check
window located at the bottom-
right side of the crankcase.TIPThe 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.
To change the engine oil (with or
without oil filter cartridge replace-
ment)
1. Place the vehicle on a level sur-
face.
2. Start the engine, warm it up for
several minutes, and then turn it
off.
3. Place an oil pan under the engine
to collect the used oil.4. Remove the cowling by removing
the bolts.
5. Remove the engine oil filler cap,
the engine oil drain bolt and its
gasket to drain the oil from the
crankcase.1. Engine oil filler cap
2. Engine oil level check window
3. Maximum level mark
4. Minimum level mark
3
4
1 2
1. Cowling
2. Bolt
1. Engine oil drain bolt
2. Gasket
1
2
12
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Periodic maintenance and adjustment
6-10
6
TIPSkip steps 6–8 if the oil filter cartridge
is not being replaced.6. Remove the oil filter cartridge with
an oil filter wrench.TIPAn oil filter wrench is available at a
Yamaha dealer.7. Apply a thin coat of clean engine
oil to the O-ring of the new oil filter
cartridge.
TIPMake sure that the O-ring is properly
seated.8. Install the new oil filter cartridge
with an oil filter wrench, and then
tighten it to the specified torque
with a torque wrench.9. Install the engine oil drain bolt and
its new gasket, and then tighten
the bolt to the specified torque.
TIPInstall the new gasket as shown.
1. Oil filter wrench
2. Oil filter cartridge
1
2
1. O-ring
1. Torque wrench
Tightening torque:
Oil filter cartridge:
17 Nm (1.7 m·kgf, 12 ft·lbf)
1
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Periodic maintenance and adjustment
6-11
6
10. Refill with the specified amount of
the recommended engine oil, and
then install and tighten the oil filler
cap.
TIPBe sure to wipe off spilled oil on any
parts after the engine and exhaust sys-
tem have cooled down.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.11. Install the cowling by installing the
bolts.
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.
TIPAfter the engine is started, the engine
oil pressure warning light should go off.NOTICE
ECA20860
If the oil pressure warning light flick-
ers or remains on even if the oil level
is correct, immediately turn the en-
gine off and have a Yamaha dealer
check the vehicle.13. Turn the engine off, wait a few
minutes until the oil settles, and
then check the oil level and cor-
rect it if necessary.
1. Engine oil drain bolt
2. GasketTightening torque:
Engine oil drain bolt:
20 Nm (2.0 m·kgf, 14 ft·lbf)
Recommended engine oil:
See page 8-1.
Oil quantity:
Oil change:
1.80 L (1.90 US qt, 1.58 Imp.qt)
With oil filter removal:
2.10 L (2.22 US qt, 1.85 Imp.qt)
2
1
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Periodic maintenance and adjustment
6-12
6
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.
EAU38176
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 the
coolant reservoir cover by remov-
ing the bolts, remove the coolant
reservoir cap, and then add cool-
ant to the maximum level mark.
WARNING! Remove only the
coolant reservoir cap. Never at-
tempt to remove the radiator
cap when the engine is hot.
[EWA15162]
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 insteadof 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. Maximum level mark
2. Minimum level mark
3. Coolant reservoir
1
2
3
1. Bolt
2. Coolant reservoir cover
2
1
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