British bike electrics were legendary for their lack of reliability causing that well know phrase - "Lighting by Lucas - the prince of darkness"

Part of the problem was that many of the brass bullets were soldered on. One should not solder anything on a bike if not essential because the molten solder is drawn into the multi-strand flexible wire by capillary action making the wire a single conductor wire and vulnerable to suffering stress fractures caused by the not inconsiderable vibration found in classic British singles and twins. Another issue is the brass corroding which can be minimised by covering the bullets and sockets in a dielectric grease of corrosion block grease.

These tools can put an end to the delights of soldering bullets. The crimp tool will fit the bullets nicely and the fitting tool squeezes the bullets into sockets which isn't a fun job without this tool