Good Ben brand 125 rack motorcycle, Zhejiang happiness machinery factory out. There are five years. Now

If you make sure that the air filter and carburetor are not clogged, and all aspects of the debugging is correct, then there is still a possibility that the clutch is slipping or the oil is not good, resulting in clutch slippage, check whether the exhaust pipe is clogged, whether the quality of the carburetor itself is too poor, whether the intake pipe is leaking, whether the valve lash is too small, whether the valve rocker arm and the camshaft are worn out, whether the spark plugs are bad, and whether the cylinder with the piston and the piston ring are worn or The valve is not closed tightly, resulting in insufficient cylinder pressure.