Part II Maintenance
8
1)
Remove the cylinder head cover bolt and the
cylinder head cover.
2)
Remove the air director plate.
3)
Rotate the flywheel to align the mark on the
flywheel with that of the air director. The No.
1 cylinder valve clearance can be adjusted.
4)
Insert a feeler gauge between the valve and
the valve rocker arm to check the clearance
5)
Then, rotate 270°, and adjust No. 2 cylinder
valve clearance.
Adjust the valve clearance
Adjustment steps: unscrew the locking nut; rotate the adjusting nut to obtain the correct valve clearance;
tighten the locking nut.
Valve clearance
Intake
0.1±0.02mm
Exhaust
0.15±0.02mm
Adjusting screw
Valve clearance
Tighten
Decrease
Loosen
Increase
Too large clearance: Late opening of intake and exhaust valves shortens the intake and
exhaust time, reduces the valve opening height, changes normal valve timing and decreases the gasoline
engine's power due to insufficient air intake and incomplete air exhaust; additionally, it also increases the
impact of valve system parts and accelerates the wear.
Too small clearance: After the gasoline engine is operated, the part is heated and expanded to push the
valve open and make the valve close loosely, which will cause air leakage, power reduction, and serious
carbon deposition or burning on the sealing surface of the valve, and even cause that the valve strikes the
piston.
Cylinder head cover bolt
Cylinder head
cover
