Checking The Valve Springs; Checking The Valve Spring Seat; Installing The Valves - Yamaha YZF-R1 Series Service Manual

j. Measure the valve seat contact width "c"
again. If the valve seat width is out of spec-
ification, reface and lap the valve seat.
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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.
Inner spring
Free length (intake)
34.52 mm (1.36 in)
Limit
32.79 mm (1.29 in)
Free length (exhaust)
36.94 mm (1.45 in)
Limit
35.09 mm (1.38 in)
Outer spring
Free length (intake)
35.72 mm (1.41 in)
Limit
33.93 mm (1.34 in)
Free length (exhaust)
36.85 mm (1.45 in)
Limit
35.01 mm (1.38 in)
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CHECKING THE VALVE SPRING SEAT

The following procedure applies to all of the
valve lifters.
VALVES AND VALVE SPRINGS
1. Check:
• Valve spring seat
Damage/scratches → Replace the valve
spring seat.
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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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2. Lubricate:
• Valve stem
• Valve stem seal
(with the recommended lubricant)
Recommended lubricant
Molybdenum disulfide oil
3. Install:
• Valve spring seat "1"
• Valve stem seal "2"
• Valve "3"
• Valve spring (inner) "4"
• Valve spring (outer) "5"
• Valve spring retainer "6"
(into the cylinder head)
TIP
• Make sure each valve is installed in its original
place.
• Install the valve springs with the larger pitch "a"
facing up.
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