Precautions In Operation - Sym GTS 250 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
ID of valve rocker arm
Rocker arm
OD of valve rocker arm shaft
OD of valve stem
ID of valve guide
Clearance between
valve stem and guide
Valve
Free length of valve
spring
Valve seat width
Valve clearance
Tilt angle of cylinder head
Torque Value
Cylinder head cover bolt
Exhaust pipe stud bolt
Cylinder head bolt
Cylinder head Nut
Sealing bolt of cam chain auto-tensioner
Bolt of cam chain auto-tensioner
Cylinder side cover bolt
Cam sprocket bolt
Tappet adjustment screw nut
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
Inner
outer
Intake
Exhaust
Standard
12±2 kg/cm2
34.880
34.740
11.982~12.000
11.966~11.984
4.975~4.990
4.950~4.975
5.000~5.012
0.010~0.037
0.025~0.062
38.700
40.400
1.600
0.10±0.02mm
0.15±0.02mm
---
1.0~1.4kgf-m
2.4~3.0kgf-m
1.0~1.4kgf-m
3.6~4.0kgf-m
0.8~1.2kgf-m
1.2~1.6kgf-m
1.0~1.4kgf-m
1.0~1.4kgf-m
0.7~1.1kgf-m
1.0~1.2kgf-m
Limit
---
34.860
34.725
12.080
11.936
4.900
4.900
5.030
0.080
0.100
35.200
36.900
---
---
---
0.050