No Power

You're going to need a wiring diagram and (quite cheap) multimeter if you fancy tackling it yourself.
It sounds like you've developed a short, check around the headstock or look around for chaffed wires i.e. under the tank, as a start.

 

I agree with Eldon, check the wiring for shorts first. If nothing is evident it might be worth checking the regulator/rectifier.

 

@JJ Smith Yes agree. Also check the fuse holders top and bottom for corrosion. But does sound like a short.