Yamaha WR250F(Y) 2009, Руководство по эксплуатации для владельца

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VALVES AND VALVE SPRINGS
CHECKING THE VALVE SPRINGS
1. Measure:
• Valve spring free length "a"
Out of specification
→
Replace.
2. Measure:
• Compressed spring force "a"
Out of specification
→
Replace.
b. Installed length
3. Measure:
• Spring tilt "a"
Out of specification
→
Replace.
CHECKING THE VALVE LIFTERS
1. Inspect:
• Valve lifter
Scratches/damage
→
Replace
both lifters and cylinder head.
INSTALLING THE VALVES
1. Apply:
• Molybdenum disulfide oil
Onto the valve stem and valve
stem seal.
2. Install:
• Valve "1"
• Valve spring seat "2"
• Valve stem seal "3"
• Valve spring "4"
• Valve spring retainer "5"
To cylinder head.
• Make sure that each valve is in-
stalled in its original place, also re-
ferring to the painted color as
follows.
Intake (middle) "a": Orange
Intake (right/left) "b": Green
Exhaust "c": Purple
• Install the valve springs with the
larger pitch "d" facing upward.
e. Smaller pitch
3. Install:
• Valve cotter
While compressing the valve spring
with a valve spring compressor "1" in-
stall the valve cotters.
4. To secure the valve cotters onto
the valve stem, lightly tap the
valve tip with a piece of wood.
Hitting the valve tip with excessive
force could damage the valve.
5. Install:
• Adjusting pad "1"
• Valve lifter "2"
• Apply the molybdenum disulfide oil
on the valve stem end.
• Apply the engine oil on the valve lift-
ers.
• Valve lifter must turn smoothly
when rotated with a finger.
• Be careful to reinstall valve lifters
and pads in their original place.
Free length (valve
spring):
Intake:
36.58 mm (1.44 in)
<Limit>: 36.81 mm
(1.45 in)
Exhaust:
35.58 mm (1.40 in)
<Limit>: 36.54 mm
(1.44 in)
Compressed spring
force:
Intake:
103–118 N at 29.13
mm (10.50–12.09 kg at
29.13 mm, 23.15–
26.66 lb at 1.15 in)
Exhaust:
126–144 N at 29.30
mm (12.85–14.68 kg at
29.30 mm, 28.32–
32.37 lb at 1.15 in)
Spring tilt limit:
Intake:
2.5°/1.6 mm (0.063 in)
Exhaust:
2.5°/1.6 mm (0.063 in)
Valve spring compres-
sor:
YM-4019/90890-04019