A bit late, but this is how the initial setting is done:

K-Jet mixture setting

After assembly of the fuel system run the fuel pump and depress the airflow sensor plate for a couple of seconds to bleed air out of the FD. Remove one injector line from the top of the FD and while looking into the injector port in the top of the FD turn the mixture adjustment screw clockwise until the port just starts to fill with fuel then turn the mixture screw 1/2 turn counter clockwise. Reinstall the injector line, start the engine and adjust mixture when it reaches operating temperature. This is the Bosch recommended procedure for initial mixture setting and adjustment.