engine YAMAHA MT-25 2016 Owner's Manual

For your safety – pre-operation checks
4-1
4
EAU15599
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.
• Check fuel tank breather hose and overflow hose for obstructions, cracks or
damage, and check hose connections.3-13, 3-15
Engine oil• Check oil level in engine.
• If necessary, add recommended oil to specified level.
• Check vehicle for oil leakage.6-9
Coolant• Check coolant level in reservoir.
• If necessary, add recommended coolant to specified level.
• Check cooling system for leakage.6-12
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.6-19, 6-20
UB04E0E0.book Page 1 Wednesday, September 2, 2015 3:51 PM

Operation and important riding points
5-1
5
EAU15952
Read the Owner’s Manual carefully to
become familiar with all controls. If
there is a control or function you do not
understand, ask your Yamaha dealer.
WARNING
EWA10272
Failure to familiarize yourself with
the controls can lead to loss of con-
trol, which could cause an accident
or injury.
EAU62513
TIPThis model is equipped with:
a lean angle sensor to stop the en-
gine in case of a turnover. In this
case, the display will indicate error
code 30, but this is not a malfunc-
tion. Turn the key to “ ” and then
to “ ” to clear the error code.
Failing to do so will prevent the en-
gine from starting even though the
engine will crank when pushing
the start switch.
an engine auto-stop system. The
engine stops automatically if left
idling for 20 minutes. If the engine
stops, simply push the start
switch to restart the engine.
EAUN0680
Starting the engineIn order for the ignition circuit cut-off
system to enable starting, one of the
following conditions must be met:
The transmission is in the neutral
position.
The transmission is in gear with
the clutch lever pulled and the
sidestand up.
See page 3-20 for more informa-
tion.
1. Turn the key to “ ” and make
sure that the engine stop switch is
set to “ ”.
The engine trouble warning light
should come on for a few sec-
onds, then go off. NOTICE: If the
warning light does not go off,
have a Yamaha dealer check its
electrical circuit.
[ECAT1121]
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.
UB04E0E0.book Page 1 Wednesday, September 2, 2015 3:51 PM

Operation and important riding points
5-2
5 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.
NOTICE
ECA10261
Even with the transmission in
the neutral position, do not
coast for long periods of time
with the engine off, and do not
tow the motorcycle for long dis-
tances. The transmission is
properly lubricated only when
the engine is running. Inade-
quate lubrication may damage
the transmission.
Always use the clutch while
changing gears to avoid dam-
aging the engine, transmission,
and drive train, which are not
designed to withstand the
shock of forced shifting.
1. Shift pedal
2. Neutral position
1
1 2
23 4 5 6N
UB04E0E0.book Page 2 Wednesday, September 2, 2015 3:51 PM

Operation and important riding points
5-3
5
EAU16811
Tips for reducing fuel con-
sumptionFuel consumption depends largely on
your riding style. Consider the follow-
ing tips to reduce fuel consumption:
Shift up swiftly, and avoid high en-
gine speeds during acceleration.
Do not rev the engine while shift-
ing down, and avoid high engine
speeds with no load on the en-
gine.
Turn the engine off instead of let-
ting it idle for an extended length
of time (e.g., in traffic jams, at traf-
fic lights or at railroad crossings).
EAU16842
Engine break-inThere is never a more important period
in the life of your engine than the period
between 0 and 1600 km (1000 mi). For
this reason, you should read the fol-
lowing material carefully.
Since the engine is brand new, do not
put an excessive load on it for the first
1600 km (1000 mi). The various parts in
the engine wear and polish themselves
to the correct operating clearances.
During this period, prolonged full-throt-
tle operation or any condition that
might result in engine overheating
must be avoided.
EAU17094
0–1000 km (0–600 mi)
Avoid prolonged operation above 7000
r/min. NOTICE: After 1000 km (600
mi) of operation, the engine oil must
be changed and the oil filter car-
tridge or element replaced.
[ECA10303]
1000–1600 km (600–1000 mi)
Avoid prolonged operation above 8400
r/min.1600 km (1000 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.
UB04E0E0.book Page 3 Wednesday, September 2, 2015 3:51 PM

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.
UB04E0E0.book Page 4 Wednesday, September 2, 2015 3:51 PM

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
UB04E0E0.book Page 1 Wednesday, September 2, 2015 3:51 PM

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)
UB04E0E0.book Page 6 Wednesday, September 2, 2015 3:51 PM

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)
UB04E0E0.book Page 8 Wednesday, September 2, 2015 3:51 PM

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
UB04E0E0.book Page 9 Wednesday, September 2, 2015 3:51 PM

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
UB04E0E0.book Page 10 Wednesday, September 2, 2015 3:51 PM