Hi Bown,
I,m guessing you want to upgrade your bike to 12 volt to get brighter lights. Technically it's possible but it probably won't make much difference. Your lights will still be pathetic as the electrical output from the Villiers flywheel magneto on the 1F is pretty minimal at best.
You are probably better off keeping the 6V system but applying the usual tricks we all did when 6V was all there was plus adding a few modern ones.
Firstly, Villiers offered two types of lighting circuit. One with a rectifier and battery and the second a "direct" lighting circuit without them. Each has their good and bad points. The good with "direct" lighting is that it uses a brighter 18 watt headlight compared with the "rectified" system that has a 12 watt headlight. The bad is that"direct" lighting depends on engine revs and goes up and down with engine speed. Mostly you get a brighter light from the "direct" circuit.
Secondly, your bike was wired with the cheapest & nastiest grade of wire that could be used. A rewire with a better quality wire helps a lot.
Thirdly, these lighting circuits use the frame etc, as a common earth return. Run an earth return line from the headlamp and tailight back to a common point on the frame so as to eliminate all possible poor contact points.
Finally, fit LED's to the tail light and hopefully a halogen headlight bulb. LED's will give as much light as the original taillight but use far less current leaving more current available for the headlight. A halogen headlight bulb gives a brighter light for the same wattage.
You can't do much to increase the tiny electrical output from the Villiers engine. All of the above is aimed at making best use of what you have.
Best of luck, Bob
