PERIODIC MAINTENANCE AND MINOR
REPAIR................................................................6-1
Tool kit..............................................................6-1
Periodic maintenance and lubrication chart......6-3
Cowling removal and installation......................6-6
Cowling A..........................................................6-6
Cowling B..........................................................6-7
Cowling C.........................................................6-8
Panel removal and installation..........................6-8
Panel D.............................................................6-9
Panel E.............................................................6-9
Spark plug.......................................................6-10
Transmission oil..............................................6-11
Cooling system...............................................6-12
Changing the coolant......................................6-13
Air filter............................................................6-15
Carburetor adjustment....................................6-16
Idle speed adjustment.....................................6-17
Throttle cable free play adjustment.................6-17
Tires................................................................6-18
Wheels............................................................6-20
Clutch lever free play adjustment...................6-21
Front brake lever free play adjustment...........6-21
Rear brake pedal height adjustment...............6-22
Brake light switch adjustment.........................6-23
Checking the front and rear brake pads.........6-23Inspecting the brake fluid level.......................6-24
Brake fluid replacement..................................6-25
Drive chain slack check..................................6-25
Drive chain slack adjustment..........................6-26
Drive chain lubrication....................................6-26
Cable inspection and lubrication.....................6-27
Throttle cable and grip lubrication...................6-27
Autolube pump adjustment.............................6-28
Brake and shift pedal lubrication.....................6-28
Brake and clutch lever lubrication...................6-28
Sidestand lubrication......................................6-29
Front fork inspection.......................................6-29
Steering inspection.........................................6-30
Wheel bearings...............................................6-30
Battery............................................................6-31
Fuse replacement...........................................6-33
Headlight bulb replacement............................6-33
Turn signal light bulb replacement..................6-35
Tail/brake light bulb replacement....................6-35
Supporting the motorcycle..............................6-36
Front wheel removal.......................................6-36
Front wheel installation...................................6-37
Rear wheel removal........................................6-38
Rear wheel installation....................................6-39
Troubleshooting..............................................6-39
Troubleshooting chart.....................................6-40
TABLE OF CONTENTS
1
2
3
4
5
6
7
8
9
6
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EAU00026
DESCRIPTION
12
3
4
5
6
7
8
9
2-1
1
23 4 5 6
7 8
9 10
Left view1.Headlight (page 6-33)
2.Radiator cap (page 6-13)
3.Fuel cock (page 3-9)
4.Air filter (page 6-15)
5.Coolant reservoir tank (page 6-13)
6.Helmet holder (page 3-12)7.Starter (choke) (page 3-10)
8.Shift pedal (page 3-5, 5-4)
9.Y.E.I.S. (page 3-14)
10.Y.P.V.S. (page 3-15)
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3-9
INSTRUMENT AND CONTROL FUNCTIONS
1
23
4
5
6
7
8
9
EC000114
cCThe following must be observed to
prevent a fire hazard or other dam-
ages.
8 8
Use only unleaded gasoline.
Use of leaded gasoline will
cause unrepairable damage to
the catalytic converter.
8 8
Never park this motorcycle in
an area that would cause a fire
hazard such as grass or other
materials that may easily burn.
8 8
Do not allow the engine to idle
for very long.
EAU03050
Fuel cockThe fuel cock supplies fuel from the
tank to the carburetor while filtering it
also.
The fuel cock has three positions:
OFF
With the lever in this position, fuel will
not flow. Always return the lever to
this position when the engine is not
running.
RES
ONFUEL
OFF
1
1.Arrow mark positioned ÒOFFÓ
EAU02956
Two-stroke engine oilMake sure there is sufficient two-
stroke engine oil in the oil tank. Add
the recommended oil as necessary.
21
1.Oil tank cap
2.Stopper
Recommended oil:
Yamalube 2 or 2-stroke
engine oil (JASO FC grade or
ISO EG-C, EG-D grade)
Oil quantity:
1.2 L
OFF: closed position
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6-3
PERIODIC MAINTENANCE AND MINOR REPAIR
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3
4
56
7
8
9
EAU03686
Periodic maintenance and lubrication chart
NOTE:
8The annual checks must be performed every year, except if a kilometer-based maintenance is performed instead.
8From 30,000 km, repeat the maintenance intervals starting from 6,000 km.
8Items marked with an asterisk should be performed by a Yamaha dealer as they require special tools, data and
technical skills.NO.ITEMCHECK OR MAINTENANCE JOBODOMETER READING (´ 1,000 km)
ANNUAL
CHECK
16121824
1
*Fuel line¥Check fuel hoses for cracks or damage.ÖÖÖÖÖ
2Spark plug¥Replace.ÖÖÖÖÖ
3Air filter element¥Clean.ÖÖ
¥Replace.ÖÖ
4*Battery¥Check electrolyte level and specific gravity.
¥Make sure that the breather hose is properly routed.ÖÖÖÖÖ
5Clutch¥Check operation.
¥Adjust.ÖÖÖÖÖ
6*Front brake¥Check operation, fluid level and vehicle for fluid leakage.
(See NOTE on page 6-5.)ÖÖÖÖÖÖ
¥Replace brake pads.Whenever worn to the limit
7*Rear brake¥Check operation, fluid level and vehicle for fluid leakage.
(See NOTE on page 6-5.)ÖÖÖÖÖÖ
¥Replace brake pads.Whenever worn to the limit
8*Brake hoses¥Check for cracks or damage.ÖÖÖÖÖ
¥Replace. (See NOTE on page 6-5.)Every 4 years
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PERIODIC MAINTENANCE AND MINOR REPAIR
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4
56
7
8
9
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.ÖÖÖÖÖÖ
22*Autolube pump¥Check operation.
¥Bleed if necessary.ÖÖÖÖ
23Transmission oil¥Check oil level.ÖÖÖÖÖÖ
¥Change.ÖÖ
24*Cooling system¥Check coolant level and vehicle for coolant leakage.ÖÖÖÖÖ
¥Change.Every 3 years
25*Front and rear brake
switches¥Check operation.ÖÖÖÖÖÖ
26Moving parts and cables¥Lubricate.ÖÖÖÖÖ
27*Lights, signals and
switches¥Check operation.
¥Adjust headlight beam.ÖÖÖÖÖÖ NO.ITEMCHECK OR MAINTENANCE JOBODOMETER READING (´ 1,000 km)
ANNUAL
CHECK
16121824
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6-15
PERIODIC MAINTENANCE AND MINOR REPAIR
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3
4
56
7
8
9
EC000080
cCHard water or salt water is harmful
to the engine. You may use dis-
tilled water if you canÕt get soft
water.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.
1
EAU03107
Air filterThe air filter should be cleaned at the
specified intervals. It should be
cleaned more frequently when riding
in unusually wet or dusty areas.
1.Remove panel D. (See page 6-9
for panel removal and installation
procedures.)
2.Remove the air filter case by
removing the screws.1.Screw (´3)
3.Remove the air filter from the
case.
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PERIODIC MAINTENANCE AND MINOR REPAIR
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2
3
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56
7
8
96.Insert the air filter guide into the
air filter and install it in the case.
7.Install the air filter case cover
and panel by installing the
screws.
EC000082
cC8
8
Make sure the air filter is prop-
erly seated in the air filter
case.
8 8
The engine should never be
run without the air filter
installed. Excessive piston
and/or cylinder wear may
result.
EAU00629
Carburetor adjustmentThe carburetor is a vital part of the
engine and requires very sophisticat-
ed adjustment. Most adjustments
should be left to a Yamaha dealer
who has the professional knowledge
and experience to do so. However,
the following may be serviced by the
owner as part of routine mainte-
nance.
EC000094
cCThe carburetor was set at the
Yamaha factory after many tests. If
the settings are changed, poor
engine performance and damage
may result.
4.Remove the air filter element
from its guide and clean it with
solvent. After cleaning, remove
the remaining solvent by squeez-
ing the element.
5.Apply recommended oil to the
entire surface of the element and
squeeze out the excess oil. It
should be wet but not dripping.
1
2
1.Guide
2.Filter element
Recommended oil:
Engine oil
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8-1
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6
78
9
EAU01038
SPECIFICATIONS
Specifications
ModelDT125R
Dimensions
Overall length2,170 mm
2,235 mm (N, S, SF, CH, A only)
Overall width830 mm
Overall height1,255 mm
Seat height885 mm
Wheel base1,415 mm
Ground clearance315 mm
Minimum turning radius2,100 mm
Basic weight (with oil and
full fuel tank)127 kg
129 kg (CH, A only)
Engine
Engine typeLiquid-cooled 2-stroke
Cylinder arrangementForward-inclined single
cylinder
Displacement124 cm
3
Bore ´Stroke56.0 ´50.7 mm Compression ratio6.7:1
Starting systemKick starter
Lubrication systemSeparate lubrication
(Yamaha autolube)
Engine oil (2-cycle)
Type2 stroke engine oil
Capacity
Total amount1.2 L
Transmission oil
TypeSAE 10W30 type SE motor oil
Capacity
Periodic oil change0.75 L
Total amount0.8 L
Radiator capacity
(Including all routes)0.92 L
Air filterWet type element
Fuel
TypeRegular unleaded gasoline
Fuel tank capacity10 L
Reserve amount1.8 L
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