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8-99
EBU00440
Troubleshooting chart
1. Fuel
Check if there is
fuel in the fuel
tank.
2. Compression
Use electric starter
to see if there is
compression.
3. Ignition
Remove plug and
check electrodes.
WetWipe clean with dry
cloth.
DryAttach plug cap and
ground to chassis.Use electric
starter.Spark weak.
Spark good.Ignition system normal.
No spark.
Ask a Yamaha dealer to inspect.
Adjust plug gap or
replace plug.
There is compresson.Compression normal.
Ask a Yamaha dealer to inspect.No compression.
There is fuel.Turn the fuel
cock to “OFF”.
Remove the
fuel hose from
the fuel cock.
Some fuel.Turn the fuel
cock to “RES”.Restart engine.
No fuel.Supply fuel.
4. Battery
Use electric
starter.
Engine turns
over quickly.Battery good.
Engine turns
over slowly.Check fluid, recharge,
check connections.
Check fuel flow.
Water or dirt
mixed in fuel.
Turn the fuel
cock to “ON”.No fuel.Fuel cock clogged.
Clean the fuel filter
and the fuel tank.
Clean fuel cock.
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9-1
EBU00418
CLEANING AND STORAGE
A. CLEANING
Frequent, thorough cleaning of your machine
will not only enhance its appearance but will
improve its general performance and extend the
useful life of many components.
1. Before cleaning the machine:
a. Block off the end of the exhaust pipe to
prevent water entry. A plastic bag and
strong rubber band may be used.
b. Make sure the spark plug and all filler
caps are properly installed.
2. If the engine case is excessively greasy,
apply degreaser with a paint brush. Do not
apply degreaser to the chain, sprockets or
wheel axles.
3. Rinse the dirt and degreaser off with a gar-
den hose. Use only enough pressure to do
the job.
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9-5
7. Clean the seat with a vinyl upholstery clean-
er to keep the cover pliable and glossy.
8. Automotive type wax may be applied to all
painted and chrome plated surfaces. Avoid
combination cleaner-waxes. Many contain
abrasives which may mar the paint or pro-
tective finish.
When finished, start the engine and let it idle
for several minutes.
w
Wet brakes may have reduced stopping abili-
ty, increasing the chance of an accident.
Test the brakes after washing. Apply the
brakes several times at slow speeds to let
friction dry out the linings.
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9-7
EBU00526
B. STORAGE
Long term storage (60 days or more) of your
machine will require some preventive procedu-
res to guard against deterioration. After tho-
roughly cleaning the machine, prepare for stora-
ge as follows:
1. Fill the fuel tank with fresh fuel and add fuel
stabilizer (if available).
NOTE:
Use of fuel stabilizer eliminates the need to
drain the fuel system. Consult a Yamaha dealer
if the fuel system is to be drained instead.
2. Remove the spark plug, pour about one
tablespoon of SAE 10W30 or 20W40 motor
oil in the spark plug hole and reinstall the
spark plug. Ground the spark plug wire and
turn the engine over several times to coat
the cylinder wall with oil.
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10-1
SPECIFICATIONS
Model YFM125
Dimensions:
Overall length 1,710 mm
Overall width 990 mm
Overall height 980 mm
Seat height 705 mm
Wheelbase 1,080 mm
Ground clearance 145 mm
Minimum turning radius 2,900 mm
Basic weight:
With oil and full fuel tank 152 kg
Noise and vibration level:
Noise level (77/311/EEC) (for Europe) 75.1db (A)
Vibration on seat (EN1032, ISO5008) (for Europe)Will not exceed 0.6 m/s
2
Vibration on handlebar (EN1032, ISO5008) (for Europe)Will not exceed 2.5 m/s2
Engine:
Engine type Air-cooled, 4-stroke, SOHC
Cylinder arrangement Singlel cylinder, Forward-inclined
Displacement 124 cm
3
Bore × stroke 49 ×66 mm
Compression ratio 9.0 : 1
Starting system Electric starter
Lubrication system Wet sump
EBU00428
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10-2
10
Model YFM125
Engine oil/final transmission oil:
Type
Recommended engine oil/final transmission API Service SE, SF, SG type or higher
oil classification:
Quantity
Engine oil:
Periodic oil change 1.25 L
Final transmission oil: 0.6 L
cC
8Do not use oils with a diesel specification
of “CD” or oils of a higher quality than
specified. In addition, do not use oils
labeled “ENERGY CONSERVING II” or
higher.
8Be sure no foreign material enters the
crankcase.
–20° 10° 20° 30° 40°
10W30
10W40
20W40
20W5050°C
0° –10°
5W30
15W40
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10-3
Model YFM125
Air filter:
for engine Wet type element
for V-belt compartment Dry type element
Fuel:
Type Unleaded gasoline only
For Europe:Regular unleaded gasoline only with a
research octane number of 91 or higher
Fuel tank capacity 7.6 L
Fuel reserve amount 1.3 L
Carburetor:
Type/manufacturer VM18SH/MIKUNI
Spark plug:
Type/manufacturer CR7HS/NGK
Gap 0.6–0.7 mm
Clutch type: Dry, centrifugal automatic
Transmission:
Primary reduction system Helical gear/Spur gear
Primary reduction ratio 43/14 ×40/17 (7.226)
Secondary reduction system Chain drive
Secondary reduction ratio 32/12 (2.666)
Transmission type V-belt automatic
Operation Centrifugal automatic type
Reverse 49/14 ×49/15 ×40/17 (26.902)
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