Precautions In Operation - Sym PA12B Service Manual

7. Cylinder Head / Valve

Precautions in Operation

General Information
This chapter includes the repair information of cylinder head, valve, camshaft, and rocker arm.
The engine must be removed before the repairing of Cylinder head.
Specification
Subject
Valve Clearance (IN/EX valve when
engine is cold)
Compression pressure
Cam Lift
Camshaft
Inner Diameter
Rocker
Arm
Outer Diameter
Valve
stem outer
diameter
Valve
Valve guide
Guide
Clearance
between
Valve stem
and guide
Valve seat width
Warpage/clearance between cylinder head
and cylinder.
Torque Value
Cylinder head nuts
Cylinder head left bolts 0.8~1.2kgf-m
Cylinder head side cover bolts 0.8~1.2kgf-m
Cam chain sprocket bolt 0.8~1.2kgf-m
Rocker arm shaft setting plate bolts
0.8~1.2kgf-m
Special tools
Valve Guide reamer 5.0mm
Valve Guide driver 5.0mm
Rocker arm shaft/ Camshaft Disassemble tool
SYM-1445100
Valve Spring Compressor SYM-1471100
Valve Spring Assemble/Disassemble Tool
7-2
To this chapter contents
IN
EX
IN
EX
IN
EX
IN
EX
2.8~3.0kgf-m
Specification
Standard
0.05 ± 0.02
12 ± 1 kg/cm²
31.983
31.119
12.000~12.018
11.984~11.966
5.450~5.465
5.430~5.455
5.4750~5.485
5.4750~5.485
0.010~0.035
0.030~0.055
1.200
─
Cylinder head tensioner bolt
Tappet adjusting cap
Valve adjusting holding nut
(Apply engine oil on threads and seats.)
Spark plug
Cylinder Head/ Engine Oil Strainer Cap
Wrench
Valve Clearance Adjustment Wrench
Measurement unit :mm
Service Limit
─
─
30.800
30.020
12.100
12.000
5.420
5.400
5.500
5.500
0.080
0.100
1.600
0.050
1.0~1.4kgf-m
1.3~1.7kgf-m
0.7~1.1kgf-m
1.0~1.2kgf-m
SYM-1471110/20
SYM-ALL23461
SYM-9001200