YAMAHA MT-03 2020 Workshop Manual

Periodic maintenance and adjustment
6-7
6
EAU19643
Checking the spark plugs
The 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.
TIP
If 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/LMAR8A-9
1. Spark plug gap
Spark plug gap:
0.8–0.9 mm (0.031–0.035 in)
Tightening torque:
Spark plug:
13 N·m (1.3 kgf·m, 9.6 lb·ft)
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Periodic maintenance and adjustment
6-8
6
EAU36112
Canister
This model is equipped with a canister
to prevent the discharging of fuel vapor
into the atmosphere. Before operating
this vehicle, make sure to check the
following:
Check each hose connection.
Check each hose and canister for
cracks or damage. Replace if
damaged.
Make sure that the canister
breather is not blocked, and if
necessary, clean it.
EAUN1150
Engine oil and oil filter car-
tridge
The 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.
TIP
The engine oil should be between the
minimum and maximum level marks.
1. Canister
1
1. Engine oil filler cap
2. Engine oil level check window
3. Maximum level mark
4. Minimum level mark
3
4
1 2
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Periodic maintenance and adjustment
6-9
6 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.
TIP
Skip steps 6…8 if the oil filter cartridge
is not being replaced.
6. Remove the oil filter cartridge with
an oil filter wrench.
TIP
An 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.
1. Cowling
2. Bolt
22
11
1. Engine oil drain bolt
2. Gasket
1. Oil filter wrench
2. Oil filter cartridge
12
1
2
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Periodic maintenance and adjustment
6-10
6
TIP
Make 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.
TIP
Install the new gasket as shown.
10. Refill with the specified amount of
the recommended engine oil, and
then install and tighten the oil filler
cap.
TIP
Be 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
1. O-ring
1. Torque wrench
Tightening torque:
Oil filter cartridge:
17 N·m (1.7 kgf·m, 13 lb·ft)
1
1. Engine oil drain bolt
2. Gasket
Tightening torque:
Engine oil drain bolt:
20 N·m (2.0 kgf·m, 15 lb·ft)
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
6-11
6 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.
TIP
After 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.
EAU85450
Why Yamalube
YAMALUBE oil is a Genuine YAMAHA
Part born of the engineers’ passion
and belief that engine oil is an impor-
tant liquid engine component. We form
teams of specialists in the fields of me-
chanical engineering, chemistry, elec-
tronics and track testing, and have
them develop the engine together with
the oil it will use. Yamalube oils take full
advantage of the base oil’s qualities
and blend in the ideal balance of addi-
tives to make sure the final oil clears
our performance standards. Thus,
Yamalube mineral, semisynthetic and
synthetic oils have their own distinct
characters and value. Yamaha’s expe-
rience gained over many years of re-
search and development into oil since
the 1960’s helps make Yamalube the
best choice for your Yamaha engine.
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Periodic maintenance and adjustment
6-12
6
EAU20071
Coolant
The 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.
EAU38176To 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.
TIP
The 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 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]
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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Periodic maintenance and adjustment
6-13
6 4. Install the reservoir cap, and then
install the coolant reservoir cover
by installing the bolts.EAU33032Changing the coolant
The coolant must be changed at the in-
tervals specified in the periodic mainte-
nance and lubrication chart. Have a
Yamaha dealer change the coolant.
WARNING! Never attempt to remove
the radiator cap when the engine is
hot.
[EWA10382]EAUN1172
Replacing the air filter ele-
ment and cleaning the check
hose
The air filter element should be re-
placed at the intervals specified in the
periodic maintenance and lubrication
chart. Replace the air filter element
more frequently if you are riding in un-
usually wet or dusty areas. In addition,
the air filter check hose must be fre-
quently checked and cleaned if neces-
sary.
To replace the air filter element
1. Remove the rider seat. (See page
3-17.)
2. Remove the left side panel bolts.
3. Remove the left side panel by re-
moving the lower projection on the
panel from the slot, and then re-
moving the upper projection as
shown.
1. Coolant reservoir cap
Coolant reservoir capacity (up to
the maximum level mark):
0.25 L (0.26 US qt, 0.22 Imp.qt)
1
1. Left side panel
2. Bolt
2 1
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Periodic maintenance and adjustment
6-14
64. Lift up the rubber covers, and then
remove the air filter case cover by
removing the screws.
5. Pull the air filter element out.
6. Insert a new air filter element into
the air filter case. NOTICE: Make
sure that the air filter element is
properly seated in the air filtercase. The engine should never
be operated without the air filter
element installed, otherwise the
piston(s) and/or cylinder(s) may
become excessively worn.
[ECA10482]
7. Install the air filter case cover by
installing the screws, and then
place the rubber covers in their
original positions.
8. Place the left side panel in the
original position, and then install
the bolts.
9. Install the rider seat.
To clean the air filter check hose
1. Check the hose on the front 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.
1. Projection
1. Air filter case cover
2. Screw
3. Rubber cover
1. Air filter element
1
12
23
1
1. Air filter check hose
1
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Periodic maintenance and adjustment
6-15
6
EAU21386
Checking the throttle grip free
play
Measure the throttle grip free play as
shown.
Periodically check the throttle grip free
play and, if necessary, have a Yamaha
dealer adjust it.
EAU21403
Valve clearance
The valves are an important engine
component, and since valve clearance
changes with use, they must be
checked and adjusted at the intervals
specified in the periodic maintenance
chart. Unadjusted valves can result in
improper air-fuel mixture, engine
noise, and eventually engine damage.
To prevent this from occurring, have
your Yamaha dealer check and adjust
the valve clearance at regular intervals.
TIP
This service must be performed when
the engine is cold.1. Throttle grip free play
Throttle grip free play:
3.0–5.0 mm (0.12–0.20 in)
1
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Periodic maintenance and adjustment
6-16
6
EAU69761
Tires
Tires 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 total
weight 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 inspection
The tires must be checked before each
ride. If the center tread depth reaches
the specified limit, if the tire has a nail
or glass fragments in it, or if the side-
wall is cracked, have a Yamaha dealer
replace the tire immediately.
Cold tire air pressure:
1 person:
Front:
200 kPa (2.00 kgf/cm2, 29 psi)
Rear:
250 kPa (2.50 kgf/cm2, 36 psi)
2 persons:
Front:
200 kPa (2.00 kgf/cm2, 29 psi)
Rear:
250 kPa (2.50 kgf/cm2, 36 psi)
Maximum load:
Vehicle:
160 kg (353 lb)
The vehicle’s maximum load is the
combined weight of the rider, pas-
senger, cargo, and any accessories.
1. Tire sidewall
2. Tire wear indicator
3. Tire tread depth
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