It is recommended to adjust the ignition time. The ignition time may be too early or too late.
You can just tune the magneto directly.
Then it is also possible that the carburetor is dirty. All you need to do is clean the carburetor. It's not a big problem.
If you don't understand something, you can go to Baichebao to ask me and I will answer you online!
If you think it is useful to you, don't hesitate to adopt it!