maintenance YAMAHA DT125R 2002 User Guide

6-8
PERIODIC MAINTENANCE AND MINOR REPAIR
6 Refer to this section each time a
panel needs to be removed and
installed.
1
1. Panel B
To install the panelPlace the panel in the original posi-
tion, and then install the screw.
1
2
1. Screw
2. Panel B
EAU04003
Panels A and B
To remove one of the panelsRemove the screw, and then pull the
panel off as shown.
1
2
1. Screw
2. Panel A
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PERIODIC MAINTENANCE AND MINOR REPAIR
6
EAU01833
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 maintenance and lubrication
chart. In addition, the condition of the
spark plug can reveal the condition of
the engine.
To remove the spark plug
1. Remove the spark plug cap.
1
1. Spark plug cap
To check the spark plug
1. Check that the porcelain insula-
tor around the center electrode
of the spark plug is a medium-to-
light tan (the ideal color when the
motorcycle is ridden normally).NOTE:
If the spark plug shows a distinctly
different color, the engine could be
defective. Do not attempt to diagnose
such problems yourself. Instead,
have a Yamaha dealer check the
motorcycle.2. Check the spark plug for elec-
trode erosion and excessive car-
bon or other deposits, and
replace it if necessary. 2. Remove the spark plug as
shown, with the spark plug
wrench included in the owner’s
tool kit.
1
1. Spark plug wrench
Specified spark plug:
BR9ES (NGK)
BR8ES (NGK) (CH, A only)
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6-10
PERIODIC MAINTENANCE AND MINOR REPAIR
6 To install the spark plug
1. Measure the spark plug gap with
a wire thickness gauge and, if
necessary, adjust the gap to
specification.
2. Clean the surface of the spark
plug gasket and its mating sur-
face, and then wipe off any grime
from the spark plug threads.
3. Install the spark plug with the
spark plug wrench, and then
tighten it to the specified torque.
a
a. Spark plug gap
EAU04272
Transmission oilThe transmission oil level should be
checked before each ride. In addition,
the transmission oil must be changed
at the intervals specified in the peri-
odic maintenance and lubrication
chart.
To check the transmission oil level
1. Place the motorcycle on a level
surface and hold it in an upright
position.NOTE:
Make sure that the motorcycle is
positioned straight up when checking
the oil level. 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.
NOTE:
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.4. Install the spark plug cap.
Spark plug gap:
0.7–0.8 mmTightening torque:
Spark plug:
20 Nm (2.0 m0kgf)
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PERIODIC MAINTENANCE AND MINOR REPAIR
63. Wait a few minutes until the oil
settles, and then check the oil
level through the check window
located at the right side of the
crankcase.
NOTE:
The transmission oil should be at or
above the minimum level mark.4. If the oil is below the minimum
level mark, remove the oil filler
cap, add sufficient oil of the rec-
ommended type to raise it to the
correct level, and then install and
tighten the cap.
1
2
1. Transmission oil level check window
2. Minimum level mark
4. Install the transmission oil drain
bolt, and then tighten it to the
specified torque.
5. Add the specified amount of the
recommended transmission oil,
and then install and tighten the
oil filler cap.
1
1. Transmission oil drain bolt
To change the transmission oil
1. Start the engine, warm it up for
several minutes, and then turn it
off.
2. Place an oil pan under the trans-
mission to collect the used oil.
3. Remove the oil filler cap and
drain bolt to drain the oil from the
transmission.
1
1. Oil filler cap
Tightening torque:
Transmission oil drain bolt:
15 Nm (1.5 m0kgf)
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PERIODIC MAINTENANCE AND MINOR REPAIR
6
EC000077
cC8In order to prevent clutch slip-
page (since the transmission
oil also lubricates the clutch),
do not mix any chemical addi-
tives with the oil.
8Make sure that no foreign
material enters the transmis-
sion.6. Start the engine, and then let it
idle for several minutes while
checking the transmission for oil
leakage. If oil is leaking, immedi-
ately turn off the engine and
check for the cause.
EAU01808
CoolantTo check the coolant level
1. Place the motorcycle on a level
surface and hold it in an upright
position.NOTE:
8The coolant level must be
checked on a cold engine since
the level varies with engine tem-
perature.
8Make sure that the motorcycle is
positioned straight up when
checking the coolant level. A
slight tilt to the side can result in
a false reading.
2. Remove panel A. (See page 6-8
for panel removal and installation
procedures.)
3. Check the coolant level in the
coolant reservoir.NOTE:
The coolant should be between the
minimum and maximum level marks.
2
1
1. Maximum level mark
2. Minimum level mark
Recommended transmission oil:
See page 8-1.
Oil quantity:
Periodic oil change:
0.75 L
Total amount (dry transmission):
0.8 L
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PERIODIC MAINTENANCE AND MINOR REPAIR
64. If the coolant is at or below the
minimum level mark, open the
reservoir cap, add coolant to the
maximum level mark, and then
close the reservoir cap.
EW000067
wNever attempt to remove the radia-
tor cap when the engine is hot.5. Install the panel.NOTE:
If the engine overheats, see page
6-45 for further instructions.
EC000080
cC8If 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.
8If water has been used instead
of coolant, replace it with
coolant as soon as possible,
otherwise the engine may not
be sufficiently cooled and the
cooling system will not be pro-
tected against frost and corro-
sion.
8If water has been added to the
coolant, have a Yamaha dealer
check the antifreeze content of
the coolant as soon as possi-
ble, otherwise the effective-
ness of the coolant will be
reduced.
Coolant reservoir capacity:
0.35 L
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PERIODIC MAINTENANCE AND MINOR REPAIR
6
EAU03101
Changing the coolant1. Put the motorcycle on a level
place.
2. Remove cowling B and panel A.
(See page 6-6–6-8 for cowling
and panel removal and installa-
tion procedures.)
3. Remove the radiator cap stopper
bolt and the radiator cap.
12
1. Radiator stopper bolt
2. Radiator cap
5. Disconnect the reservoir tank
hose on the reservoir tank side
and drain the coolant from the
reservoir tank.
6. After draining the coolant, thor-
oughly flush the cooling system
with clean tap water.
7. Replace the coolant drain bolt
washer if it is damaged and tight-
en the coolant drain bolt to the
specified torque.
1
1. Reservoir tank hose
4. Place a container under the
engine and remove the coolant
drain bolt.
1
1. Coolant drain bolt
Tightening torque:
Coolant drain bolt:
10 Nm (1.0 m0kgf)
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PERIODIC MAINTENANCE AND MINOR REPAIR
68. Install the reservoir tank hose.
9. Pour the recommended coolant
into the radiator until it is full.10. Install the radiator cap.
11. Run the engine several minutes.
Stop the engine and recheck the
coolant level in the radiator. If it
is low, add more coolant until it
reaches the top of the radiator.
12. Install the radiator cap stopper
bolt.
13. Fill the reservoir tank with
coolant up to maximum level.
14. Install the reservoir tank cap and
check for coolant leakage.
NOTE:
If any leakage is found, ask a
Yamaha dealer to inspect the cooling
system.15. Install the cowling and the panel.
EC000080
cC8If 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.
8If water has been used instead
of coolant, replace it with
coolant as soon as possible,
otherwise the engine may not
be sufficiently cooled and the
cooling system will not be pro-
tected against frost and corro-
sion.
8If water has been added to the
coolant, have a Yamaha dealer
check the antifreeze content of
the coolant as soon as possi-
ble, otherwise the effective-
ness of the coolant will be
reduced.
Recommended antifreeze:
High quality ethylene glycol
antifreeze containing corrosion
inhibitors for aluminum engines.
Antifreeze and water mixing ratio:
1:1
Total amount:
1.05 L
Reservoir tank capacity:
0.35 L
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PERIODIC MAINTENANCE AND MINOR REPAIR
6
EAU04233
Cleaning the air filter
elementThe air filter element should be
cleaned at the intervals specified in
the periodic maintenance and lubrica-
tion chart. Clean the air filter element
more frequently if you are riding in
unusually wet or dusty areas.
1. Remove panel A. (See page 6-8
for panel removal and installation
procedures.)
2. Remove the air filter case cover
by removing the screws.
1
2
1. Screw (×3)
2. Air filter case cover
4. Remove the wing nut, and then
separate the air filter element
from the guide.
5. Remove the sponge material
from the frame, clean it with sol-
vent, and then squeeze the
remaining solvent out.
6. Apply oil of the recommended
type to the entire surface of the
sponge material, and then
squeeze the excess oil out.NOTE:
The sponge material should be wet
but not dripping.
12
3
4
1. Air filter element guide
2. Air filter element frame
3. Sponge material
4. Wing nut
3. Remove the air filter element
from the case.
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PERIODIC MAINTENANCE AND MINOR REPAIR
67. Pull the sponge material over the
frame.
8. Install the air filter element onto
the guide, and then tighten the
wing nut.
9. Insert the air filter element into
the case.
10. Install the air filter case cover by
installing the screws.
11. Install the panel.
EC000082
cC8Make sure that the air filter ele-
ment is properly seated in the
air filter case.
8The engine should never be
operated without the air filter
element installed, otherwise
the piston and/or cylinder may
become excessively worn.
EAU00632
Adjusting the engine idling
speedThe engine idling speed must be
checked and, if necessary, adjusted
as follows at the intervals specified in
the periodic maintenance and lubrica-
tion chart.
1. Start the engine and warm it up
for several minutes at 1,000–
2,000 r/min while occasionally
revving it to 4,000–5,000 r/min.NOTE:
The engine is warm when it quickly
responds to the throttle.2. Check the engine idling speed
and, if necessary, adjust it to
specification by turning the throt-
tle stop screw.
EAU00629
Adjusting the carburetorThe carburetor is an important part of
the engine and requires very sophisti-
cated adjustment. Therefore, most
carburetor adjustments should be left
to a Yamaha dealer, who has the
necessary professional knowledge
and experience. The adjustment
described in the following section,
however, may be serviced by the
owner as part of routine mainte-
nance.
EC000094
cCThe carburetor has been set and
extensively tested at the Yamaha
factory. Changing these settings
without sufficient technical knowl-
edge may result in poor perfor-
mance of or damage to the engine.
Recommended oil:
2-stroke engine oil
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