www.kayomoto.us
- 36 -
Engine maintenance manual
Cylinder head and valve
Maintenance instructions
Troubleshooting
Cylinder head cover disassemble
cylinder head disassemble
Disintegrate cylinder head cover
Disintegrate the cylinder head
Inspection of valves and valve springs
Inspection of rocker arm and rocker shaft
Inspection of camshaft components
Inspection of the cylinder head
Inspection and grinding of valve seat
Examination of valve guide
Valve guide replacement
Measure the width of the valve seat contact
surface
Cylinder head assembly
Cylinder head assembly
Cylinder head installation
Installation of the cylinder head cover
Maintenance instructions
Precautions:
● The lubrication of the camshaft is lubricated through the oil passage on the cylinder head and the
oil hole on the rocker shaft. The oil passage on the cylinder head must not be allowed to enter, and it
is required to keep smooth.
● Before installing the cylinder head, the cylinder head positioning pin must be assembled.
● The camshaft must not be scratched. Lubricate with oil before assembly.
Maintenance parameters of each component
Item
Standard mm
Maintanence Limit
mm
Axial clearance between rocker arm and cylinder head cover rocker
0.05
～
0.3
0.5
Radial clearance between rocker arm and rocker shaft
0.016
～
0.045
0.08
Valve spring free length
48.35
47.5
Valve clearance
0.04
～
0.06
------
Camshaft base circle runout
0.02
0.04
valve
Valve stem outer
diameter
Intake
φ4.972
～
φ4.987
φ4.96
exhaust
φ4.96
～
φ4.975
φ4.94
Inner diameter of
valve guide
Intake
φ5
～
φ5.012
φ5.035
exhaust
φ5
～
φ5.012
φ5.035
Valve stem and
catheter clearance
Intake
0.013
～
0.04
0.07
Intake
0.25
～
0.052
0.08
Valve seal width
1.5
----
Cylinder head
Flatness
0.04
0.05
Valve seat working surface width
0.8
----
