Installing The Valves - Yamaha MBK MW125 2014 Service Manual

b. Installed length
3. Measure:
• Valve spring tilt "a"
Out of specification → Replace the valve
spring.
Spring tilt (intake)
1.5 mm (0.06 in)
Spring tilt (exhaust)
1.5 mm (0.06 in)
EAS30288

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"
Recommended lubricant
Molybdenum disulfide oil
VALVES AND VALVE SPRINGS
• Valve stem seal "2"
(with the recommended lubricant)
Recommended lubricant
Engine oil
3. Install:
• Valve spring seat "1"
• Valve stem seal "2"
• Valve "3"
• Valve spring "4"
• Valve spring retainer "5"
(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.
1
3
b. Smaller pitch
4. Install:
• Valve cotters "1"
5-26
E
New
5
4
2
New