I have a CB750K7 ignition that Im planning on relocating on my bike. I also have an ignition from a 750K3 that is a lot smaller in size that I'd rather use since it'll fit better in the place I want to relocate. The K7 ignition has 5 wires, the K3 has 4. Can anyone let me know what the 5th is for? Can I make the K3 work in the K7?