Cylinder Head/Valve; Preparatory Data - KEEWAY RKV125 Instruction And Maintenance Manual

XII Cylinder Head/Valve

Preparatory data-----------------12.1

Fault diagnosis------------------12.2
Cylinder head--------------------12.3
Valve Inspection---------------- 12.4
12.1 Preparatory Data
Precautions on Operation
To ensure sealing between cylinder head and cylinder body, there is a great bolt pretension on the cylinder head.
Pretension value: 50Nm.
All the components shall be cleaned before inspection and test, and purged with high-pressure air.
Function of cylinder head:
hold high-temperature and high-pressure fuel gas. It accomplishes air intake and exhausting operation with valve
mechanism.
Basic Data
Valve clearance
Valve stem OD
Valve
Valve guide Valve guide ID
Clearance between valve stem and valve guide
Valve race width
Valve
Clearance
spring
Rocker arm shaft OD
Rocker arm
Rocker arm hole ID
Valve
Clearance between rocker arm shaft and rocker arm
Valve guide
hole
Cylinder head is used to seal cylinder and form a combustion chamber with piston to
Item
Cylinder cover flatness
Valve guide replacement-------------12.5
Valve race fixing and adjustment---12.6
Cylinder head installation------------12.7
Intake
Exhaust
Intake
Exhaust
Intake
Exhaust
Intake
Exhaust
Intake/Exhaust
Intake/Exhaust 11.980-11.988
Intake/Exhaust
Intake/Exhaust
Unit
: mm
Service
Standard Limit
0.03 0.05
＿
0.03-0.05
＿
0.03-0.05
4.97-4.98 4.9
4.96-4.97 4.9
5 -5.012 5.1
5-5.012 5.1
0.02-0.042 0.08
0.03-0.052 0.10
0.7 1.5
38.8 37.8
11.95
12-12.012 12.05
0.012-0.032 0.08