Hey alan0899, thanks for the reply.
Changed the plug to a new one (F type) after experimenting the same problem with the old one.
As far as I can tell (have not yet done the pinch test and will do it) I have it as lean as can be. The engine dies if I go any more to the lean side (this engine lean is screw out, counter clockwise).
Now the prop does seem to be holding the engine some from full to iddle. Is not as smooth, but it slows down rather rapid. This is why I thought the advice to change prop to 13-4 was ok.
I appreciate any comments, thanks.

HM