2004 YAMAHA YZF-R1S Service Manual

5-27
VALVES AND VALVE SPRINGSENG
NOTE:
NOTE:
NOTE:
NOTE:
EAS00237
REMOVING THE VALVES
The following procedure applies to all of the
valves and related components.
Before removing the internal parts of the cylin-
der head (e.g., valves, valve springs, valve
seats), make sure the valves properly seal.
1. Remove:

valve lifter
1

valve pad 2
Make a note of the position of each valve lifter
and valve pad so that they can be reinstalled in
their original place.
2. Check:

valve sealing
Leakage at the valve seat
Check the valve
face, valve seat, and valve seat width.
Refer to “CHECKING THE VALVE SEATS”.
a. Pour a clean solvent
a into the intake and
exhaust ports.
b. Check that the valves properly seal.
There should be no leakage at the valve seat
1.
3. Remove:

valve cotters
1
Remove the valve cotters by compressing the
valve spring with the valve spring compressor
2 and the valve spring compressor attachment
3.
Valve spring compressor
90890-04019, YM-04019
Valve spring compressor
attachment
Intake valve
90890-04114, YM-4114
Exhaust valve
90890-04108, YM-4108
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5-28
VALVES AND VALVE SPRINGSENG
NOTE:
NOTE:
4. Remove:

upper spring seat
1

valve spring 2

valve stem seal 3

lower spring seat 4

valve 5
Identify the position of each part very carefully
so that it can be reinstalled in its original place.
EAS00239
CHECKING THE VALVES AND VALVE
GUIDES
The following procedure applies to all of the
valves and valve guides.
1. Measure:

valve-stem-to-valve-guide clearance
Valve-stem-to-valve-guide clearance =
Valve guide inside diameter
A –
Valve stem diameter
B
Out of specification
Replace the valve
guide.
Valve-stem-to-valve-guide
clearance
Intake
0.0010
0.0037 mm
(0.0004
0.0015 in)
: 0.08 mm (0.0032 in)
Exhaust
0.025
0.052 mm
(0.0010
0.0020 in)
: 0.10 mm (0.0039 in)
2. Replace:

valve guide
To ease valve guide removal and installation,
and to maintain the correct fit, heat the cylinder
head to 100C (212F) in an oven.
a. Remove the valve guide with the valve guide
remover
1.
b. Install the new valve guide with the valve
guide installer
2 and valve guide remover
1.
c. After installing the valve guide, bore the
valve guide with the valve guide reamer
3 to
obtain the proper valve-stem-to-valve-guide
clearance.
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5-29
VALVES AND VALVE SPRINGSENG
NOTE:
NOTE:
After replacing the valve guide, reface the valve
seat.
Valve guide remover
Intake (4.0 mm, 0.16 in)
90890-04111
Exhaust (4.5 mm, 0.18 in)
90890-04116, YM-4116
Valve guide installer
Intake (4.0 mm, 0.16 in)
90890-04112
Exhaust (4.5 mm, 0.18 in)
90890-04117, YM-4117
Valve guide reamer
Intake (4.0 mm, 0.16 in)
90890-04113
Exhaust (4.5 mm, 0.18 in)
90890-04118, YM-4118
3. Eliminate:

carbon deposits
(from the valve face and valve seat)
4. Check:

valve face
Pitting / wear
Grind the valve face.

valve stem end
Mushroom shape or diameter larger than the
body of the valve stem
Replace the valve.
5. Measure:

valve margin thickness
a
Out of specification
Replace the valve.
Valve margin thickness
0.5
0.9 mm
(0.0197
0.0354 in)
: 0.5 mm (0.02 in)
6. Measure:

valve stem runout
Out of specification
Replace the valve.

When installing a new valve, always replace
the valve guide.

If the valve is removed or replaced, always re-
place the oil seal.
Valve stem runout
0.01 mm (0.0004 in)
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5-30
VALVES AND VALVE SPRINGSENG
NOTE:
NOTE:
EAS00240
CHECKING THE VALVE SEATS
The following procedure applies to all of the
valves and valve seats.
1. Eliminate:

carbon deposits
(from the valve face and valve seat)
2. Check:

valve seat
Pitting / wear
Replace the cylinder head.
3. Measure:

valve seat width
a
Out of specification
Replace the cylinder
head.
Valve seat width
Intake: 0.9
1.1 mm
Intake: (0.0354
0.0433 in)
Exhaust: 0.9
1.1 mm
Exhaust: (0.0354
0.0433 in)
: 1.6 mm (0.06 in)
a. Apply Mechanic’s blueing dye (Dykem)
1
onto the valve face.
b. Install the valve into the cylinder head.
c. Press the valve through the valve guide and
onto the valve seat to make a clear impres-
sion.
d. Measure the valve seat width.
Where the valve seat and valve face contacted
one another, the blueing will have been re-
moved.
4. Lap:

valve face

valve seat
After replacing the cylinder head or replacing
the valve and valve guide, the valve seat and
valve face should be lapped.
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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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5-33
VALVES AND VALVE SPRINGSENG
NOTE:
NOTE:
NOTE:
2. Lubricate:

valve stem
1

valve stem seal 2
(with the recommended lubricant)
Recommended lubricant
Molybdenum disulfide oil
3. Install:

valve
1

lower spring seat 2

valve stem seal 3

valve spring 4

upper spring seat 5
(into the cylinder head)
Install the valve spring with the larger pitch
a
facing up.
bSmaller pitch
Make sure that each valve is installed in its origi-
nal place. Refer to the following embossed
marks.
Right and left intake valve(-s): “5VY :”
Middle intake valve(-s): “5VY
.”
Exhaust valve(-s): “5VY”
4. Install:

valve cotters
1
Install the valve cotters by compressing the
valve spring with the valve spring compressor
2 and the valve spring compressor attachment
3.
Valve spring compressor
90890-04019, YM-04019
Valve spring compressor
attachment
Intake valve
90890-04114, YM-4114
Exhaust valve
90890-04108, YM-4108
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5-34
VALVES AND VALVE SPRINGSENG
CAUTION:
NOTE: 5. To secure the valve cotters onto the valve
stem, lightly tap the valve tip with a soft-face
hammer.
Hitting the valve tip with excessive force
could damage the valve.
6. Install:

valve pad
1

valve lifter 2

Lubricate the valve lifter and valve pad with
molybdenum disulfide oil.

The valve lifter must move smoothly when ro-
tated with a finger.

Each valve lifter and valve pad must be rein-
stalled in its original position.
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