The negative pressure membrane of the carburetor is damaged. Signs of pressure leakage 

The most critical part of the CV series carburetor should be the negative pressure membrane. Once it was damaged, it would leave a big hole, but I have also encountered it where the small gap gradually turned into a large gap step by step, and it may not be possible to ride faster. I really didn’t know that he was broken, so I came to see what was going on in the dead of night!
By the way... I couldn't remember the name of the auxiliary fuel injection (accelerator pump) in the video, and even referred to it as TPS. I would like to apologize to you all!