BVF 22N2 setup

[alexan]

hi how are you? ... sorry for my english
I'm spanish and I have a mz etz 125. IT's very old and with several mistakes.
I'm not sure if the carburetor is properly regulated. Air screw 1,5 revolutions, and with regulation screw I have the moto about 1300 - 1400 rpm, I think this is correct... but...
Whats the rigth position of the jet needle? it's 4 positions and I don't know about it.

Thanks