Zontes ZT310M 2022, Руководство по обслуживанию

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4. Camshaft
a. Check whether the return position of the camshaft pressure reducing valve is normal.
b. Check the camshaft pick for abnormal wear.
c. Rotate the camshaft bearing by hand, and it should rotate smoothly and without abnormal noise.
Item Standard value Repair limit value
Camshaft tip
height
Inlet tip height
(a)
39.996-40.116 mm
（
1.5746-1.5794 in
）
39.896 mm
（
1.5707 in
）
Exhaust tip
height (b)
39.946-40.066 mm
（
1.5727-1.5774 in
）
39.846 mm
（
1.5687 in
）
Camshaft Camshaft
runout
- 0.03mm
（
0.0012 in
）
5. Intake valve, exhaust valve, cylinder head seat ring
a. Check whether the valve stem diameter is abnormally worn, bent or ablated, and check whether the valve can
move smoothly in the valve guide.
b. Check whether the valve seat ring surface is abnormally worn or ablated.
C. Check the seat ring surface of the cylinder head, and there is no abnormal wear or ablation.
Item Standard value Repair limit value
Matching clearance between valve
stem diameter and valve guide
Intake 0.01-0.037 mm
（
0.0004-0.0015 in
）
0.08 mm
（
0.0032 in
）
exhaust 0.025-0.052 mm
（
0.0010-0.0020 in
）
0.1 mm
（
0.0039 in
）
Valve stem diameter beat - 0.01 mm
（
0.0004 in
）
(Note: The matching clearance between the valve stem diameter and the valve guide tube is the value
obtained by subtracting the valve stem diameter from the outer diameter of the guide tube,when the fit
clearance exceeds the maintenance limit value, please judge the amount of wear of the valve guide and valve
stem diameter. After replacing the new parts with large wear, whether it is within the fitting standard value. If it
is, replace it, if it is not, replace the cylinder head and valve.)
Camshaft bearing
Pressure reducing
valve rejection block
Camshaft
b
a
Valve seat
surface
Cylinder head seat
ring surface
Valve stem diameter
Inner diameter of valve guide