Yamaha YZFR1W 2007, Service Manual

Page: 228 / 429

VALVES AND VALVE SPRINGS
5-28
EAS24320
CHECKING THE VALVE LIFTERS
The following procedure applies to all of the
valve lifters.
1. Check:
• Valve lifter
Damage/scratches
→
Replace the valve
lifters and cylinder head.
EAS24340
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:
• Valve “1”
• Lower spring seat “2”
• Valve stem seal “3”
• Valve spring “4”
• Upper spring seat “5”
(into the cylinder head)
NOTE:
• Make sure each valve is installed in its origi-
nal place. Refer to the following embossed
marks.
Intake valve: Pink paint mark
Exhaust valve: “4C8”
• Install the valve springs with the larger pitch
“a” facing up.
4. Install:
• Valve cotters “1”
NOTE:
Install the valve cotters by compressing the
valve spring with the valve spring compressor
“2” and the valve spring compressor attach-
ment “3”.
Spring tilt limit
Spring tilt (intake)
2.5
°
/1.7 mm
Spring tilt (exhaust)
2.5
°
/1.7 mm
Recommended lubricant
Molybdenum disulfide oil
b. Smaller pitch