Precautions In Operation - Sym HD 125 Service 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
rocker arm.
Cylinder head service can be carried out when engine is in frame.
Specification
Compression pressure
Camshaft Height of cam lobe
Rocker arm ID of valve rocker arm
OD of valve rocker arm shaft
Valve OD of valve stem
Guide seat
Clearance between
valve stem and guide
Free length of valve spring
Valve seat width
Tilt angle of cylinder head
Torque Value
Cylinder head bolt (LH)
Cylinder head Nut
Sealing bolt of cam chain auto-tensioner
Bolt of cam chain auto-tensioner
Cam sprocket cover bolts
Cam sprocket bolt
Spark plug
Tools
Special service tools
Valve reamer: 5.0mm
Valve guide driver: 5.0mm
Valve spring compressor
6-2
To this chapter contents
Item
Intake
Exhaust
Intake
Exhaust
Intake
Exhaust
Standard
12+/2 kg/cm2
30.800~30.920
30.411~30.531
12.000~12.018
11.966~11.984
4.975~4.990
4.955~4.970
5.000~5.012
0.010~0.037
0.030~0.057
35.000
1.000
---
2.0~2.4kgf-m
2.0~2.4kgf-m
0.8~1.2kgf-m
1.2~1.6kgf-m
0.8~1.2kgf-m
0.8~1.2kgf-m
1.0~1.2kgf-m
Limit
---
3.075
30.26
12.10
11.910
4.900
4.900
5.030
0.080
0.100
31.500
1.6
0.05