That sound you keep refrencing is called four-stroking. Its doing that up top becuase it is too rich on the main jet. Get the main right an it will run clean in the higher rpms and youll be going faster. Read up on simple carb tuning and rejet accordingly.
The problem with swapping og parts to the chinese clone is that the two units are not going to be manufactured to the same specs and its basically a craps shoot whether any swapped parts will actually work. Youre much better off finding an original carb.
And stop saying you've done "everything" because you obviously haven't.