I recently installed a 123 distributor to my 970 S engine. One set of instructions told me to set the static timing mark at TDC , then time the 123 to this.Another set of instructions told me to set the static timing at 10BTDC. I tried both ways, but 10 BTDC is the one to use!!!!
The designer of the 123 insists the TDC should be used, but the vendor insists that 10 BTDC be used. There must be a change of programming, because 10 works. TDC makes it run retarded!

From memory to static time it you put the dissy in pointing to number 1 at TDC then turn it counter clockwise until the green LED lights up. I think you have the black wire disconnected at this point. That is at about 10 BTDC. You then check it with a timing light looking to set 10 BTDC at idle. Its all in the instructions online though.