Cylinder Head/Valve - Sym ALA125CC Manual

6. CYLINDER HEAD/VALVE

PRECAUTIONS IN OPERATION
General Information
This chapter is contained maintenance and service for cylinder head, valve, and camshaft
as well as valve rocker arm.
Cylinder head service cannot be carried out when engine is in frame.
Specification
Compression pressure
Height of cam lobe
Camshaft
ID of valve rocker arm
Rocker
arm
OD of valve rocker arm shaft
OD of valve stem
Clearance between
valve stem and guide
Valve
Free length of valve
spring
Connection Flatness of cylinder head
Torque Value
Cylinder head cover bolts
Holder nuts
Cylinder head bolts
Valve adjustment fixing nuts
Camshaft chain auto-adjuster bolts
Timing gear cover bolts
Spark plug
TOOLS
Special service tools
Valve reamer: 5.0mm
Valve guide driver: 5.0mm
Valve spring compressor
6-2
Item
Intake
Exhaust
Intake
Exhaust
OD of Guide
Intake
Exhaust
Outer
Inner
Valve seat width
Standard
13 kgf/cm²
25.965
25.81
10.00
10.00
5.00
5.00
5.00
0.020~0.045
0.030~0.057
32.56
35.25
1.000
-
0.8~1.2kgf-m
1.0~1.5kgf-m
0.8~1.2kgf-m
1.0~1.5kgf-m
0.8~1.2kgf-m
0.7~1.1kgf-m (apply with oil on bolt thread & seat)
1.0~1.4kgf-m
SYM
unit: mm
Limit
-
25.290
25.120
10.000~10.015
9.985~10.00
4.975~4.99
4.97~4.98
5.030
0.080
0.100
32.26
34.75~35.75
1.600
0.050