5-19
VALVES AND VALVE SPRINGS
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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.
a. Apply a coarse lapping compound “a” to the
valve face.
CAUTION:
Do not let the lapping compound enter the
gap between the valve stem and the valve
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.
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.
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g. Install the valve into the cylinder head.
h. Press the valve through the valve guide and
onto the valve seat to make a clear impres-
sion.
i. Measure the valve seat width “c” again. If the
valve seat width is out of specification, reface
and lap the valve seat.
5-20
VALVES AND VALVE SPRINGS
2. Measure:
• Compressed valve spring force “a”
Out of specification
→
Replace the valve
spring.
3. Measure:
• Valve spring tilt “a”
Out of specification
→
Replace the valve
spring.
INSTALLING THE VALVES
The following procedure applies to all of the
valves and related components.
1. Deburr:
• Valve stem end
(with an oil stone)
2. Lubricate:
• Valve stem “1”
• Valve stem seal “2”
(with the recommended lubricant)
3. Install:
• Lower spring seat “1”
Free length (intake)
41.71 mm
Limit
39.62 mm
Free length (exhaust)
41.71 mm
Limit
39.62 mm
Installed compression spring
force (intake)
140–162 N (31.47–36.42 lbf)
(14.28–16.52 kgf)
Installed compression spring
force (exhaust)
140–162 N (31.47–36.42 lbf)
(14.28–16.52 kgf)
Installed length (intake)
35.30 mm
Installed length (exhaust)
35.30 mm
b. Installed length
Spring tilt (intake)
2.5°/1.8 mm
Spring tilt (exhaust)
2.5°/1.8 mm
Recommended lubricant
Molybdenum disulfide oil
New
Summary of Contents for YZF-R15
Page 1: ...2008 SERVICE MANUAL YZF R15 20P F8197 E0 ...
Page 33: ...2 14 ELECTRICAL SPECIFICATIONS Coil resistance 54 0 66 0 Fuse 20 0A Ω Fuse ...
Page 46: ...2 27 LUBRICATION POINTS AND LUBRICANT TYPES LUBRICATION DIAGRAMS A 1 2 3 4 5 6 7 ...
Page 48: ...2 29 LUBRICATION POINTS AND LUBRICANT TYPES 1 2 3 4 ...
Page 49: ...2 30 LUBRICATION POINTS AND LUBRICANT TYPES 1 Camshaft 2 Crankshaft 3 Main axle 4 Drive axle ...
Page 50: ...2 31 COOLING SYSTEM DIAGRAMS COOLING SYSTEM DIAGRAMS 1 2 3 4 1 5 7 6 4 ...
Page 52: ...2 33 CABLE ROUTING CABLE ROUTING 1 5 2 3 6 4 8 7 ...
Page 54: ...2 35 CABLE ROUTING A A B B C C A A C C B B A B C 1 2 3 4 5 4 5 6 6 7 8 9 10 11 10 11 12 12 ...
Page 56: ...2 37 CABLE ROUTING 1 2 5 4 3 ...
Page 60: ...2 41 CABLE ROUTING A A B C D E 1 2 3 4 5 6 7 8 9 10 A ...
Page 121: ...4 24 FRONT BRAKE Refer to BLEEDING THE HYDRAULIC BRAKE SYSTEM on page 3 18 ...
Page 249: ...7 8 THROTTLE BODY ...
Page 250: ...7 9 AIR INDUCTION SYSTEM AIR INDUCTION SYSTEM 1 2 5 4 5 6 3 2 1 6 4 3 ...
Page 257: ......
Page 269: ...8 12 CHARGING SYSTEM 1 AC magneto 2 Rectifier regulator 3 Battery 42 Fuse ...
Page 271: ...8 14 CHARGING SYSTEM ...
Page 275: ...8 18 LIGHTING SYSTEM ...
Page 285: ...8 28 COOLING SYSTEM ...
Page 311: ...8 54 FUEL PUMP SYSTEM ...