Here is the SME series II improved manual.
Now if you look at the last pages 15 and 16, you can see the rubber grommets in the arm base. You can also see there is a gap between the arm base and the turntable motor board.
If the arm base is hard against the motor board that is your problem, most likely. It could also be that the turntable is a lousy design with a resonant motor board.
I have never been a fan of Far Eastern turntables. I have personally only used Garrard and Thorens.
This is how it should look.
This is one of my SME series III arms. It is on a Thorens TD 150.
This is my other SME series III arm on a Thorens TD 125 Mk II turntable.