the left front cover;
(2) rotate the rotor of the magneto so that the rotor
timing scale line "----" is aligned with the timing mark
on the left front cover;
(3) After the timing mark is corrected, observe the O
engraving of the timing driven sprocket and the timing
mark on the cylinder head is corrected;
Only when both (2) and (3) are satisfied can the engine
be in the correct timing position.
Note:
①
When assembling the timing bolt, do not drop the bolt
into the cylinder;
②
Timing sprocket bolt torque: 7 ~ 11N·m.
6. Adjust the clearance between the inlet and exhaust
doors and turn the crankshaft counterclockwise for two
weeks to align the timing sprocket O mark with the
cylinder head timing mark.
(1) Axial slight clearance, no clearance up and down;
(2) Check the valve clearance with the feeler, its value
should be in the range of 0.01-0.03mm;
(3) tightening torque of the nut: 8 ~ 12N·m.
7. Combine the φ 6× φ 13×2 aluminum gasket with the
hexagon pan head bolt GB5787 M6x110, put it through
the hole on the right cover of the cylinder head into the
threaded hole on the left cover of the cylinder head
(gasket), and tighten the bolt, tightening torque: 8 ~
12N·m
8. Put the O-ring into the groove of the valve cover, and
then install the valve cover on the cylinder head and
tighten, fastening torque: 8 ~ 12N·m.
9. Put the spark plug into the spark plug thread of the
cylinder head and tighten it.
Fastening torque: 10 ~ 12N·m.
Cylinder block and piston
Matters needing attention
◆
Cylinder head lubricating oil is through the oil hole next to the left AB bolt of the engine to the cylinder head.
Before installing the cylinder block, ensure that the oil hole next to the left AB bolt is unimpeded, otherwise it is
easy to cause engine damage;
◆
Can not make dust or dust into the crankcase.
Main parameters and maintenance standards of cylinder block and piston
No.
Items
Standard value
Maintenance limit value
Remark
1
Cylinder
block
Cylinder diameter
Φ52.4~φ52.41
Φ52.418
Cylindricity
0.005
0.01
Flatness of cylinder
0.04
0.06
2
Piston
Skirt diameter, H=7
Φ52.375~φ52.385
Φ52.36
Pin holes diameter
φ13.002~φ13.008
φ13.017
Clearance between the
piston pin and the piston
pin hole
0.001~0.012
0.025
3
Piston
ring
closed
interval
First
ring
0.1~0.25
0.4
