Solex 34 PICT 3 main needle

I've realized that the main needle angular position on Solex 34 PICT 3 carburetor has some sharpened difficulty that has some relations with automatic choke control. As the 3ird party manufactured carb. used Bocar is mounted in my VW 1302 Super Beetle, a principle to adjust the original position 2 and a half turning back from the tightened angular position is not always meet with mine.
Probably, former user of this Bocar might have tighten too much in, so the needle valve hole must have been enlarged illegally.
Consequently, the angular position of main needle valve should be decided by my cut & try method repeatedly, very small and keen adjustment is required under this condition, not impossible but available. 470 degree turning back position of mixture control screw is my setting as a matter of fact.
Though the procedure for it relies on my sense and experience, mainly rely on exhaust smell, too much lean mixture produces excessive Hydro-Carbon and too rich Oxidized-Carbon instead.
Of course, spark firing timing and timing acceleration construction, both vacuum and centrifugal has much to do with the motor's combustion.
Because have I a struggled experience on Weber 40 DCOM side draft  twin carburetor as long as 10 years originally embedded in Peugeot Talbot 205 Rallye, the single carburetor adjustment is not so difficult task for me.
With mechanical Weber side draft twin carburetors, Regular Government Continuity Inspection had been passing instead of Private.
Experienced mechanic servicemen should know how difficult it had been on Earth?
I always say to myself and to my son, only experiences make a man.
Asking anything to others means being stolen precious and indispensable treasures by the others.