Valve And Valve Spring Removal; Valve And Valve Spring Inspection - Yamaha EF1000iS Service Manual

CYLINDER (CRANKCASE 1) AND VALVE
3
2
1
a
a

VALVE AND VALVE SPRING REMOVAL

1. Remove:
9 Spring retainer 1
9 Valve spring 2
9 Valve 3
NOTE:
Press the spring retainer by your finger while
removing the spring retainer.

VALVE AND VALVE SPRING INSPECTION

1. Measure:
9 Valve stem diameter a
Out of specification → Replace.
Valve stem diameter:
3.96 ~ 3.98 mm (Intake)
(0.156 ~ 0.157 in)
3.94 ~ 3.96 mm (Exhaust)
(0.155 ~ 0.156 in)
Limit:
3.92 mm (Intake)
(0.154 in)
3.90 mm (Exhaust)
(0.153 in)
2. Measure:
9 Valve stem runout
Out of specification → Replace.
Valve stem runout limit:
0.01 mm (0.0004 in)
NOTE:
The value is half of that indication on the dial
gauge.
3. Measure:
9 Valve spring free length a
Out of specification → Replace.
Valve spring free length:
25.0 mm (0.984 in)
(Intake/Exhaust)
Limit:
24.0 mm (0.945 in)
3-31
ENG