The Vape conversion to 12 v system with electronic ignition is known as Powerdynamo in Europe. I have fitted 2 off these systems to Benelli 250 2c’s. They work very well and are straight forward to fit, you need to replace the horn, bulbs, flasher unit and battery to 12v as well. When fitted the bike tick over and ran so much better and the lights worked like a modern bike!
i can’t help you with carburation as that model was not sold in Europe!