I switched some wires around on the taillight, and it works better. It still only uses one filament, but it's not so incredibly bright that it burns out the bulb and kills the engine at idle. My brother was riding it around yesterday, and he noticed something else strange. when you position the headlight switch between on and off positions, it gets amazingly bright and the engine kills when you hit the brakes (just like the brakelight did before I switched the wires on it.) the bike is working pretty good right now, aside from a dim headlight. What do you mean by a wire in his "headset" not being connected to anything? What did he end up connecting it to?
Thanks for all the help,