14
lock with 10 mm wrench
Locking torque: about 8 N·m~12 N·m
g) Take out the 10 mm and 14 mm wrenches, measure the air valve clearance with the feeler
gauge slightly; if the clearance is too large or small, repeat the steps c~f;
h) Adjust the valve clearance of another air valve with the same method;
i) Power on the engine, observe whether the valve rocker is operated normally; if it is
abnormal, it indicates that the top dead center is false timing, turn the engine to true timing
and repeat the above steps.
j) Mount new gasket to make it tightly connect with the cylinder head.
k) Install the cylinder head cover, tighten 4 bolts according to specified torques.
Torque values: 10 ± 2 N·m
Standard value of valve clearance
Intake valve
0.10-0.15 mm
Exhaust valve
0.15-0.20 mm
Adjusting nut
Valve clearance
Tighten
Decrease
Loosen
Increase
Excessive gap: 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.
Excessive little 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 the valve strikes the piston.
3-6 Governor
Governor adjustment:
The machine speed under mower status has been adjusted before delivery, no adjustment shall
