Measure the inner diameter of each valve guide with a
dial indicator and record it. Maintenance limit
value:φ5.035 mm
Note:
Before measuring the id of the valve guide, the
carbon deposit in the valve guide should be completely
removed.
If the valve guide needs to be replaced, the valve seat
should be re-ground surface treatment, and the valve
inserted into the guide, observe its movement, and
finally calculate the clearance between the valve rod and
the valve guide.
Valve clearance maintenance limits:
Intake
：
0.07 mm
；
Exhaust
：
0.08mm.
Replacement of valve guide
1.Put the cylinder head in the thermostat to heat to 100 ~ 150 degrees Celsius, take out and support the cylinder
head (pay attention not to burn), remove with the valve. Install the tool and punch the valve guide to the side of the
rocker arm chamber.
2.Press the new valve guide into place and reaming the newly installed valve guide after the cylinder head cools.
3.The cylinder head is cleaned with cleaning agent and the metal chips in the cylinder head are removed with
compressed air.
Note:
Do not damage the cylinder head when removing the valve guide.
Note:
when reaming, apply cutting oil on the reamer, and rotate the reamer when loading or taking it out.
Measure width of valve seat contact area
1.Measure width of valve seat contact area. Maintenance limit value: 1.5mm
2.If the valve seat is too wide, too narrow or dented, the valve seat should be ground to achieve the correct degree
of sealing.
3.When grinding the valve, use the electric gun sleeve on the rubber hose (with a tight fit), and then the valve rod
sleeve on the rubber hose, the grinding graphite paste coated on the valve sealing belt, and then attached to the
valve seat sealing line, start the electric gun, turn the valve, the valve and the seat ring with grinding.
4.After grinding, check whether the sealing line between valve and seat ring has been ground out, otherwise,
regrinding should be done. Truthfully, the valve or cylinder head should be replaced if the grinding is not in place.
Assembly of cylinder head
1.Install the oil baffle on the valve guide;
2.After the inlet and exhaust valve rod is coated with
lubricating oil, load the valve guide, install the valve
spring, valve spring seat and valve lock clip;
3. Press the valve spring with the valve remover, and
then clamp the valve lock into the valve spring seat;
Note: To prevent permanent deformation of the valve
spring, do not compress the spring too much to fit the
valve lock clip.
4. Check whether the valve lock clip assembly is in
place;
5. Conduct air tightness test on the assembled cylinder
head assembly. If there is no leakage of the cylinder
head assembly, proceed to the next step.
6. The camshaft into cylinder head CAM shaft hole and
assembly in place, then turn the CAM CAM direction
downward, rocker arm curved surface on the base circle
of the camshaft in the rocker, rocker arm shaft outward
