Re: Magneto-powered headlights
The trouble is that pulling anything over about 3W from the white wire is going to impact CDI performance. This doesn't leave a whole lot of juice to power a bulb.
Someone on eBay sells an add-on mag coil that fits next to the existing coil, and then you can run all your electrical off of that. I really like that idea, but the setup for sale is prohibitively expensive. If I were an electronics geek, I would try to engineer something like that myself, and get it manufactured cheaply enough to sell at a reasonable price.