That guy on tbe bmwmotorcycletech site has an explanation which I can't quite remember about how the modules differ. Either module will work for electric start but only one will get it started if you are kick-starting it. Part numbers also on his site, Google is your friend on this one. I think the modules with purple part number is the kick start one. When kick starting you have to open the throttle to let gas on and you have to give it a few good kicks too to allow the intake stroke to suck on the carb. I'd imagine it will work better with smaller carbs but I'm just guessing.
Glad you still enjoy my old bike Jim I was wondering about the old guy I bought it from(via dealership) in 2007, he must be seriously old now if indeed he is still above ground in the fatherland.