Check if the muffler is installed;

Check if the muffler is tightened or damaged;

If the above phenomenon occurs, replace the muffler and check if the machine's sound is normal;

If it is confirmed that there is no problem with the muffler, it indicates that it is an internal problem with the machine head, which can be divided into two situations:

① The inner cup and cylinder liner of the machine head are severely worn. After disassembly, it can be judged by the naked eye. If the sound is normal after replacement, it indicates that it is caused by the wear of this vulnerable component; If there is still abnormal sound, it indicates that the bearing inside the machine head is damaged.

② The simplest way to determine if there is a problem with the bearing is to disassemble it and rotate it by hand. Listen for obvious clicking sounds, and if there is, it indicates that the bearing is damaged; If there is no such abnormal sound, it cannot be determined whether there is a problem. It needs to be installed on the machine head for testing to determine if there is a problem