headlight questions

Incandescant lights are AC/DC. They don't care. Any 6 volt lamp will work but you need to check the wattage. The white wire from your engine (magneto) is only rated to give you about 3 watts. That's not a very big lamp. Some of the LED style of lamps will give you good light even at 3 watts, enough to be seen but don't expect to light up the street in front of you with it. Same for the tail light. There has been a lot of discussion here about using the white wire to trickle charge a 6 volt battery. The battery would power your lights and the white wire will replenish the charge; at least in theory. I don't know if anyone has done this successfully yet. I use a 6 volt, 7 amp hour SLA (sealed lead acid) battery for both of my lights and simply hook it up to a trickle charger when the bike is parked in the garage. It gives me a good hour of light, more than I've ever needed for night rides. Hope this helps you. Good luck