ZHEJIANG KAYO MOTOR CO., LTD.
www.kayomoto.com
40
Overhauling the Engine
Cylinder head and valve mechanism I
Note
:
1.
Make sure valve clearance meet the standards after each disassembly work of rocker group.
2.
Keep the oil passage on cylinder head cover is open.
3.
Install the locating pin before mounting the cylinder head.
Main parameters and maintenance standards of cylinder head parts
Item
Standard value (mm)
Maintenance ( mm)
Push rod length
135.85
～
136.15
135.80
Left and right backlash of rocker group
0.1~0.3
0.35
Free length of valve spring
22.7~24.7
22.5
Valve clearance
0.02
～
0.04
/
Valve
Valve guide
Valve stem outer diameter
Air inlet
φ5.45
～
φ5.465
φ5.43
Air inlet
φ5.43~φ5.445
φ5.41
Valve stem inner diameter
Air inlet
φ5.475~φ5.487
φ5.53
Air inlet
φ5.475~φ5.487
φ5.53
Clearance between valve
rod and valve guide
Air inlet
0.01~0.037
0.07
Air inlet
0.03~0.057
0.09
Valve line width
Air inlet
2.8
/
Air inlet
1.4
/
Cylinder head
Flatness
0.03
0.1
Valve seat width
0.71~0.99
1.2
spark plug
Clearance
0.6
～
0.7
/