Weichai America Corp.
22
the gas generator. If the valve does not sink more than the allowable value, remove the valve
check valve and valve seat sealing surface, check valve and valve seat sealing surface for
obvious wear and tear and abnormal damage.
Table 3-3 Valve Depression Requirements
Valve Depression Requirements
（
mm
）
Intake
-0.2~0.2
exhaust
-0.22~0.22
5.
After disassembling the valve body, check the condition of the cylinder head into the exhaust
port to see if there is any water leakage. If there is any such problem, it should be washed and
shaded. To confirm the problem position, you need to replace the new cylinder head.
6.
Clean the cylinder head, focus on cleaning the surface of the combustion chamber, seat,
intake and exhaust valves, inlet and outlet channels, remove the surface area of carbon and
viscose, and check the surface condition.
7.
Check the diameter of the valve guide tube, valve guide tube valve inner diameter of the
contact surface with the valve movement, if the valve guide tube diameter due to wear
exceeds the allowable value, it will affect the valve guide effect to reduce the reliability of the
engine work. Measuring the diameter of the valve guide can be measured using an ID
micrometer, as shown in Figure 4-14. The allowable range of valve guide diameter is: (9.0 ~
9.015) mm, the cylinder head needs to be replaced if the allowable range is exceeded to
ensure the reliability of engine operation.
Figure 3-6 Micrometer inside diameter
8.
Remove the cylinder head gasket and check for visible damage to the cylinder head gasket
and analyze the cause.
Document Courtesy of Fly Parts Guy Co.
www.FlyPartsGuy.com
Document Courtesy of Fly Parts Guy Co.
www.FlyPartsGuy.com
