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8-17
7. Fill the engine with oil and install the dip-
stick.
cC
Be sure no foreign material enters the
crankcase.
8. Warm up the engine for several minutes at
idle speed. Check for oil leakage while
warming up.
cC
If oil leakage is found, stop the engine imme-
diately and check for the cause.
Recommended oil type:
20W50, 20W40, 15W40, 10W40,
10W30, 5W30
Recommended oil classification:
API Service SE, SF, SG type or higher
Oil quantity:
Periodic oil change:
0.8L
5YF-9-60 8 4/24/03 6:35 PM Page 8-17
Page 274 of 350

2
1
1. Fastener 2. Air filter element1. Attache 2. Elément du filtre à air1. Sujeción 2. Elemento filtrante de aire
8-29
2. Remove the air filter case cover by
unhooking the fasteners.
3. Remove the air filter element by unhooking
the fastener.
4. Wash the air filter element gently but thor-
oughly in solvent.
w
Always use parts cleaning solvent to clean
the air filter element. Never use low flash
point solvents or gasoline to clean the air fil-
ter element because the engine could catch
fire or explode.
5. Squeeze the excess solvent out of the air
filter element and let it dry.
cC
Do not twist the air filter element when
squeezing it.
6. Inspect the air filter element. If damaged,
replace it.
7. Apply Yamaha foam air filter oil or other
quality foam air filter oil to the air filter ele-
ment. If foam air filter oil is not available,
SAE10W30 motor oil may be used.
q
ww
1. Air filter case cover 2. Fastener (×4)1 . Couvercle du boîtier de filtre à air 2 .Attache (×4)1.Cubierta de la caja del filtro de aire2. Sujeción (×4)
5YF-9-60 8 4/24/03 6:35 PM Page 8-29
Page 296 of 350
8-51
EBU00570
Cable inspection and lubrication
w
Inspect cables frequently and replace if dam-
aged. Corrosion can result when the outer
covering of control cables becomes dam-
aged. Cables can also become frayed or
kinked. Operation of controls could be
restricted, which could cause an accident or
injury.
Lubricate the inner cables and the cable ends. If
the cables do not operate smoothly, ask a
Yamaha dealer to replace them.
Recommended lubricant:
Engine oil
5YF-9-60 8 4/24/03 6:35 PM Page 8-51
Page 326 of 350
9-7
EBU00427
B. STORAGE
Long term storage (60 days or more) of your
machine will require some preventive proce-
dures to guard against deterioration. After thor-
oughly cleaning the machine, prepare for stor-
age 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 rein-
stall the spark plug. Ground the spark plug
wire and turn the engine over several times
to coat the cylinder wall with oil.
3. Lubricate all control cables.
5YF-9-60 9~ 4/24/03 6:34 PM Page 304
Page 330 of 350
10-1
Model YFM50
Dimensions:
Overall length 1,537 mm
Overall width 825 mm
Overall height 915 mm
Seat height 618 mm
Wheelbase 1,030 mm
Ground clearance 70 mm
Minimum turning radius 2,300 mm
Basic weight:
With oil and full fuel tank 115 kg
Engine:
Type Air-cooled 4-stroke, SOHC
Cylinder arrangement Single cylinder, forward-inclined
Displacement 49.0 cm
3
Bore × Stroke 39.0 ×41.4 mm
Compression ratio 10.0 : 1
Starting system Electric starter
Lubrication system Wet sump
EBU00428
SPECIFICATIONS
5YF-9-60 9~ 4/24/03 6:34 PM Page 308
Page 331 of 350
10-2
10
MODEL YFM50
Engine oil:
Type
Recommended engine oil classification: API Service SE, SF, SG type or higher
Quantity:
Periodic oil change 0.80 L
cC
In order to prevent clutch slippage (since the
engine oil also lubricates the clutch), do not
mix any chemical additives. Do 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.
–20° 10° 20° 30° 40°
10W30
10W40
20W40
20W5050°C
0° –10°
5W30
15W40
5YF-9-60 9~ 4/24/03 6:34 PM Page 309