The white wire that comes off our HT motors can power some lights, but if you did that you'd be taking away electrical power from the spark plug.
This modification possibly solves that problem. Now you can power your lights from your engine and keep your spark power! From the looks of it, it's a smaller separate magneto coil. That way you're getting power separately and not taking it away from the main magneto coil.
If you don't want to build one of these yourself(I don't even know how), you can buy the the entire system on eBay! Ebay user mightywonderful is selling the Mini-Gen Max, which is a complete separate power system for your motorized bicycle.
A warning to those looking to mod their motorized bicycles:
Most, if not all, of the hacks and mods featured on this site were made by individual hobbyists. If you are new to working with 2-stroke bicycle engines, please by aware that there's a possibility that a mod featured on this site could seriously damage your engine. Please don't try any mod from this or any other site unless you fully understand what you are doing. The owner of this blog will not be held responsible for both material and bodily damage caused by performing a modification featured on this blog. Also remember that opening up your engine may void your warranty!