2002 YAMAHA DT125R check engine

5-1
EAU00372
OPERATION AND IMPORTANT RIDING POINTS
5
EAU00373
w8Become thoroughly familiar
with all operating controls and
their functions before riding.
Consult a Yamaha dealer
regarding any control or func-
tion that you do not thorough-
ly understand.
8Never start the engine or oper-
ate it in a closed area for any
length of time. Exhaust fumes
are poisonous, and inhaling
them can cause loss of con-
sciousness and death within a
short time. Always make sure
that there is adequate ventila-
tion.
8Before starting out, make sure
that the sidestand is up. If the
sidestand is not raised com-
pletely, it could contact the
ground and distract the opera-
tor, resulting in a possible loss
of control.
EAU01177
Starting a cold engineIn order for the ignition circuit cut-off
system to enable starting, one of the
following conditions must be met:
8The transmission is in the neutral
position.
8The transmission is in gear with
the clutch lever pulled and the
sidestand up.
EW000054
w8Before starting the engine,
check the function of the igni-
tion circuit cut-off system
according to the procedure
described on page 3-17.
8Never ride with the sidestand
down.
1. Turn the fuel cock lever to “ON”.
2. Turn the key to “ON” and make
sure that the engine stop switch
is set to “#”.
3. Shift the transmission into the
neutral position.NOTE:
When the transmission is in the neu-
tral position, the neutral indicator light
should be on, otherwise have a
Yamaha dealer check the electrical
circuit.
ON
FUEL
RES
OFF
1
ON
1. Arrow mark positioned over “ON”
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5-4
OPERATION AND IMPORTANT RIDING POINTS
5
EAU00436
Engine break-inThere is never a more important peri-
od in the life of your engine than the
period between 0 and 1,000 km. 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 1,000 km. The various parts in
the engine wear and polish them-
selves to the correct operating clear-
ances. During this period, prolonged
full-throttle operation or any condition
that might result in engine overheat-
ing must be avoided.
EAU00453
0–500 km
8Avoid prolonged operation above
6,000 r/min.
8After every hour of operation,
stop the engine, and then let it
cool for five to ten minutes.
8Vary the engine speed from time
to time. Do not operate the
engine at one set throttle posi-
tion.
500–1,000 km
8Avoid prolonged operation above
7,000 r/min.
8Rev the engine freely through
the gears, but do not use full
throttle at any time.
EC000060
cCAfter 1,000 km of operation, the
transmission oil must be changed.
1,000 km and beyond
The vehicle can now be operated
normally.
EC000053
cC8Keep the engine speed out of
the tachometer red zone.
8If any engine trouble should
occur during the engine break-
in period, immediately have a
Yamaha dealer check the vehi-
cle.
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6-4
PERIODIC MAINTENANCE AND MINOR REPAIR
6
EAU03884
NOTE:
8The air filter needs more frequent service if you are riding in unusually wet or dusty areas.
8Hydraulic brake service
9Regularly check and, if necessary, correct the brake fluid level.
9Every two years replace the internal components of the brake master cylinders and calipers, and change the
brake fluid.
9Replace the brake hoses every four years and if cracked or damaged.21
*Carburetor•Check starter (choke) operation.
•Adjust engine idling speed.√√√√√ √
22*Autolube pump•Check operation.
•Bleed if necessary.√√√√
23 Transmission oil•Check oil level.√√√√√ √
•Change.√√
24*Cooling system•Check coolant level and vehicle for coolant leakage.√√√√ √
•Change.Every 3 years
25*Front and rear brake
switches•Check operation.√√√√√ √
26 Moving parts and cables•Lubricate.√√√√ √
27*Lights, signals and
switches•Check operation.
•Adjust headlight beam.√√√√√ √ NO. ITEM CHECK OR MAINTENANCE JOBODOMETER READING (× 1,000 km)
ANNUAL
CHECK
1 6 12 18 24
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6-9
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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6-11
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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6-12
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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6-13
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
3MB-9-E8 6/13/01 10:55 AM Page 50