Operational Precautions - Sym Mio 50 Service Manual

6. Cylinder Head / Valve

Operational Precautions

General Information
This chapter is contained maintenance and service for cylinder head, valve, and camshaft as well as
rocker arm.
Cylinder head service cannot be carried out when engine is in frame.
Specification
Model
Item
Valve clearance (intake/exhaust valve
as cold engine)
Compression pressure
Camshaft height of cam
lobe
ID of valve rocker arm
Rocker
arm
OD of valve rocker arm shaft
OD of valve stem
Guide seat
Clearance
Valve
between valve
stem and guide
Valve seat width
Connection Flatness of cylinder head
Torque Value
Cylinder head bolt (LH)
Cylinder head left side bolt
Cylinder head Nut
Sealing bolt of timing chain auto-tensioner
Bolt of timing chain auto-tensioner
Valve adjustment nuts
Spark plug
Special service tools
Valve reamer: 5.0mm
Valve guide driver: 5.0mm
Valve cover wrench SYM-ALL12361
Valve spring compressor SYM-1471100 0r
Valve spring compressor/installer SYM-1471110/20
Valve clearance adjustment wrench SYM-9001200 or
Valve clearance adjuster SYM-9001210
6-2
To this chapter contents
HU10U/W
Standard
0.12 ± 0.02
12 ± 2 kg/cm²
25.969
Intake
25.891
Exhaust
10.000~10.015
9.972~9.987
4.975~4.985
Intake
4.955~4.970
Exhaust
5.000~5.012
0.010~0.037
Intake
0.030~0.057
Exhaust
1.000
-
1.0~1.4kgf-m
1.0~1.4kgf-m
1.8~2.2kgf-m
0.8~1.2kgf-m
1.0~1.4kgf-m
0.7~1.1kgf-m (apply with oil on bolt thread & seat)
1.0~1.4kgf-m
HU05U
Limit Standard
─ 0.05/ 0.10 ± 0.02
─ 9 ± 2 kg/cm²
25.570 24.100
25.410 23.850
10.100 10.000~10.015
9.910 9.987~9.978
4.900 4.980~4.970
4.900 4.970~4.955
5.300 5.000~5.012
0.080 0.010~0.037
0.100 0.030~0.057
1.600 1.000
0.050 -
Unit: mm
Limit
─
─
23.761
23.369
10.100
9.910
4.900
4.900
5.300
0.080
0.100
1.600
0.050