The CDI box for this bike is p/n M04016000 there is a black wire that comes out of the CDI that is supposed to be connected to a chassis ground. I do not see your CDI box in this picture. to the best of my memory the CDI box is approx. 70mm long x 15mm x 15mm there are 2 x 3 wire connectors going to it, one on each end.
Good luck.