2004 YAMAHA YZF-R1SC length

4-49
FRONT FORKCHAS
NOTE:
WARNING
4. Remove:

damper rod assembly bolt

damper rod assembly
While holding the damper rod assembly with the
damper rod holder
1, loosen the damper rod
assembly bolt.
Damper rod holder
90890-01423, YM-01423
EAS00656
CHECKING THE FRONT FORK LEGS
The following procedure applies to both of the
front fork legs.
1. Check:

inner tube
1

outer tube 2
Bends / damage / scratches
Replace.
Do not attempt to straighten a bent inner
tube as this may dangerously weaken it.
2. Measure:

spring free length
a
Out of specification
Replace.
Spring free length
236.5 mm (9.31 in)
: 231.8 mm (9.13 in)
3. Check:

damper rod
1
Damage / wear
Replace.
Obstruction
Blow out all of the oil pas-
sages with compressed air.

damper rod adjusting rod
Bends / damage
Replace.
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4-73
SWINGARM AND DRIVE CHAINCHAS
NOTE: 3. Wash:

pivot shaft

dust covers

spacer

washers

bearings
Recommended cleaning solvent
Kerosene
4. Check:

dust covers
1

spacer 2
Damage / wear
Replace.

bearings
3
Damage / pitting
Replace.
5. Check:

connecting arms
1

relay arm 2
Damage / wear
Replace.
6. Check:

bearings
3

oil seals 4
Damage / pitting
Replace.
7. Check:

collars
5
Damage / scratches
Replace.
EAS00709
CHECKING THE DRIVE CHAIN
1. Measure:

ten-link section
a of the drive chain
Out of specification
Replace the drive
chain.
Ten-link drive chain section limit
(maximum)
150.1 mm (5.91 in)

While measuring the ten-link section, push
down on the drive chain to increase its tension.

Measure the length between drive chain roller
1 and 11 as shown.

Perform this measurement at two or three dif-
ferent places.
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5-31
VALVES AND VALVE SPRINGSENG
CAUTION:
NOTE:
a. Apply a coarse lapping compound a to the
valve face.
Do not let the lapping compound enter the
gap between the valve stem and the valve
guide.
b. Apply molybdenum disulfide oil onto the
valve stem.
c. Install the valve into the cylinder head.
d. Turn the valve until the valve face and valve
seat are evenly polished, then clean off all of
the lapping compound.
For the best lapping results, lightly tap the valve
seat while rotating the valve back and forth be-
tween your hands.
e. Apply a fine lapping compound to the valve
face and repeat the above steps.
f. After every lapping procedure, be sure to
clean off all of the lapping compound from
the valve face and valve seat.
g. Apply Mechanic’s blueing dye (Dykem) onto
the valve face.
h. Install the valve into the cylinder head.
i. Press the valve through the valve guide and
onto the valve seat to make a clear impres-
sion.
j. Measure the valve seat width
a again. If the
valve seat width is out of specification, reface
and lap the valve seat.
EAS00241
CHECKING THE VALVE SPRINGS
The following procedure applies to all of the
valve springs.
1. Measure:

valve spring free length
a
Out of specification
Replace the valve
spring.
Valve spring free length
Intake valve spring
39.3 mm (1.55 in)
: 37.3 mm (1.47 in)
Exhaust valve spring
39.3 mm (1.55 in)
: 37.3 mm (1.47 in)
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5-32
VALVES AND VALVE SPRINGSENG
2. Measure:

compressed valve spring force
a
Out of specification
Replace the valve
spring.
bInstalled length
Compressed valve spring force
(installed)
Intake valve spring
145.9
167.9 N
(14.88
17.12 kg,
32.80
37.74 lb) at
32.65 mm (1.285 in)
Exhaust valve spring
164.1
188.9 N
(16.73
19.26 kg,
36.89
42.46 lb) at
32.82 mm (12.92 in)
3. Measure:

valve spring tilt
a
Out of specification
Replace the valve
spring.
Spring tilt limit
Intake valve spring
1.7 mm (0.07 in)
Exhaust valve spring
1.7 mm (0.07 in)
EAS00242
CHECKING THE VALVE LIFTERS
The following procedure applies to all of the
valve lifters.
1. Check:

valve lifter
Damage / scratches
Replace the valve lift-
ers and cylinder head.
EAS00245
INSTALLING THE VALVES
The following procedure applies to all of the
valves and related components.
1. Deburr:

valve stem end
(with an oil stone)
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5-53
CLUTCHENG
NOTE:
NOTE:
EAS00282
CHECKING THE CLUTCH SPRINGS
The following procedure applies to all of the
clutch springs.
1. Check:

clutch spring
Damage
Replace the clutch springs as a
set.
2. Measure:

clutch spring free length
a
Out of specification
Replace the clutch
springs as a set.
Clutch spring free length
52.5 mm (2.07 in)
: 49.9 mm (1.96 in)
EAS00284
CHECKING THE CLUTCH HOUSING
1. Check:

clutch housing dogs
Damage / pitting / wear
Deburr the clutch
housing dogs or replace the clutch housing.
Pitting on the clutch housing dogs will cause er-
ratic clutch operation.
2. Check:

bearing
Damage / wear
Replace the bearing and
clutch housing.
EAS00285
CHECKING THE CLUTCH BOSS
1. Check:

clutch boss splines
Damage / pitting / wear
Replace the clutch
boss.
Pitting on the clutch boss splines will cause er-
ratic clutch operation.
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8-22
STARTER MOTORELEC
NOTE: 5. Measure:

brush length
a.
Out of specification
Replace the brushes
as a set.
Brush length wear limit
3.6 mm (0.14 in)
6. Measure:

brush spring force
Out of specification
Replace the brush
springs as a set.
Brush spring force
5.28  7.92 N
(538  808 gf, 18.99  28.48 oz)
7. Check:

gear teeth
Damage / wear
Replace the gear.
EAS00772
ASSEMBLING THE STARTER MOTOR
1. Install:

brush seat
1
Align the slot a on the brush seat with the tab b
in the starter motor rear cover.
2. Install:

armature
1
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