Multi-cylinder misfire problem.
For multiple cylinder misfire problems, you need to check if the mixture is normal, if there is an air leak in the intake air, If the spark plug has misfired and if the ignition coil also needs to be checked. The oil head is not smooth and excessive carbon deposits in the engine may be the cause, so check it.
Hello Bingbing; Based on what you said, you can check in two parts. First, check whether the engine ignition and fuel supply are normal, and see if there are misfires and poor fuel supply. Second, check whether the gearbox input shaft friction plate is worn out of tolerance. There are many faults that cause accidents: mixture ratio failure, ignition problems, intake and exhaust problems, mmechanical, etc...