Hi guys, thnx for your reactions. I have already fixxed the needle and cleaned and oiled the cable. The internal gear of the meter wasn't dried out and contained still grease. I guess the only thing left is that the cable is to old and has probably to much flex so i will replace that.
Other thing that came to my mind is that i have lowered the forcplates so i coould place the clipons on top of the upper plate for a better sitting position. Now the cable has to bend a bit more and is causing the flutter!? First i replace it for a new one.
Cheers Richard.