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3-6
INSTRUMENT AND CONTROL FUNCTIONS
3
EAU03753
FuelMake sure that there is sufficient fuel
in the tank. Fill the fuel tank to the
bottom of the filler tube as shown.
EW000130
w8Do not overfill the fuel tank,
otherwise it may overflow
when the fuel warms up and
expands.
8Avoid spilling fuel on the hot
engine.
1
2
1. Filler tube
2. Fuel level
ECA00104
cCUse only unleaded gasoline. The
use of leaded gasoline will cause
severe damage to internal engine
parts, such as the valves and pis-
ton rings, as well as to the exhaust
system.Your Yamaha engine has been
designed to use regular unleaded
gasoline with a research octane num-
ber of 91 or higher. If knocking (or
pinging) occurs, use a gasoline of a
different brand or premium unleaded
fuel. Use of unleaded fuel will extend
spark plug life and reduce mainte-
nance costs.
EAU00185
cCImmediately wipe off spilled fuel
with a clean, dry, soft cloth, since
fuel may deteriorate painted sur-
faces or plastic parts.
EAU04284
Recommended fuel:
REGULAR UNLEADED
GASOLINE ONLY
Fuel tank capacity:
Total amount:
7.0 L
Reserve amount:
1.0 L
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8-1
EAU01038
SPECIFICATIONS
8
Specifications
Model TW125
Dimensions
Overall length 2,135 mm
Overall width 820 mm
Overall height 1,120 mm
Seat height 820 mm
Wheelbase 1,350 mm
Ground clearance 255 mm
Minimum turning radius 2,100 mm
Basic weight (with oil and full
fuel tank)127 kg
Engine
Engine type Air-cooled 4-stroke, SOHC
Cylinder arrangement Forward inclined
single cylinder
Displacement 124 cm
3
Bore ×Stroke 57.0 ×48.8 mm
Compression ratio 10:1
Starting system Electric starter
Lubrication system Wet sumpEngine oil
Type
Recommended engine oil
classification API Service SE, SF, SG type
or higher
cCBe sure to use motor oils that do not contain anti-friction
modifiers. Passenger car motor oils (often labeled “ENERGY
CONSERVING II”) contain anti-friction additives which will
cause clutch and/or starter clutch slippage, resulting in
reduced component life and poor engine performance.
Capacity
Without oil filter element
removal 1.0 L
With oil filter element removal 1.1 L
Total amount (dry engine) 1.3 L
–10° 0° 10° 20° 30°
40°
SAE 10W/30
SAE 10W/40
SAE 20W/40
SAE 20W/50
–20°
SAE 15W/40 50°C
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8-2
SPECIFICATIONS
8
Air filterWet type element
Fuel
Type REGULAR UNLEADED
GASOLINE ONLY
Fuel tank capacity 7.0 L
Reserve amount 1.0 L
Carburetor
Manufacturer TEIKEI
Model ×quantity MV28 ×1
Spark plug
Manufacturer/Type NGK/DR8EA
Gap 0.6–0.7 mm
Clutch typeWet, multiple-disc
Transmission
Primary reduction system Spur gear
Primary reduction ratio 74/20 (3.700)
Secondary reduction system Chain drive
Secondary reduction ratio 3.643
Number of drive chain
sprocket teeth (rear/front) 51/14
Transmission type Constant mesh 5-speed
Operation Left foot operationGear ratio 1st 2.250
2nd 1.476
3rd 1.125
4th 0.926
5th 0.793
Chassis
Frame type Diamond
Caster angle 25.83°
Trail 93 mm
Tires
Front
Type With tube
Size 130/80-18 66P
130/80-18 M/C 66P
Manufacturer/ BRIDGESTONE/TW-203
model
Rear
Type With tube
Size 180/80-14 M/C 78P
Manufacturer/ BRIDGESTONE/TW-204
model
5RS-9-E0 (TW125) 7/30/01 6:03 PM Page 80