Check valve clearance
Check at initial 1000km and every 5000km. Excessive valve clearance will lead to valve noise, while too
small valve clearance will cause engine power reduction and valve damage. Valve clearance should be
checked according to the above specified mileage and adjusted according to the following steps:
Remove the valve cover
Unscrew the magneto plug and timing plug on the left front cover and turn the magneto rotor with a 14mm
socket wrench until the piston reaches the top dead center of compression stroke (turn the magneto rotor until
the cut line on the rotor aligns with the timing hole on the left front cover).
Insert the standard gauge between the adjusting screws on the valve rod end and rocker arm, and the inlet and
exhaust valve clearance is 0.03 ~ 0.05mm.
If the valve clearance is not within the range mentioned above, use a special tool to adjust it within the
specified range.
Reinstall the valve cover, magneto plug and timing plug.
Note:
The valve clearance should be checked and adjusted in the engine cooling condition.
Inspection of compression pressure
Check at initial 1000km and every 5000km. The inspection steps is as follows:
Warm the engine by idling the engine.
Unscrew the spark plug.
Install the pressure gauge and connector into the spark plug mounting hole and make sure the connection is
firm.
Turn the throttle handle to full open position.
Start the engine several times with the starter motor and read the maximum pressure of the engine cylinder as
indicated by the pressure gauge.
standard values
1200~1250Pa
limit value
1100Pa
Low pressure indicates the following faults:
Excessive wear of cylinder walls.
Wear of piston or piston ring.
Piston ring stuck in ring groove. The valves are not properly engaged to the valve seat.
cylinder gasket damaged. When the compression pressure of the engine is lower than the above limit, the
engine should be reassembled, inspected and repaired according to the specific situation.
Note:
Before testing the engine compression pressure, make sure that the cylinder nuts and bolts are tightened
according to the specified torque and the valve clearance is adjusted correctly.
Adjustment of clutch control system
In order to ensure the correct use of the clutch and the portable operation, the user should ensure that the
clutch is in the normal state of engagement, not allowed to be in a semi-clutch state.
