So when my fuel pump did not prime I started to check the wiring for the kill switch and found that one of the wires had been disconnected. How would I go about reattaching it? Soldering it back on? It is the black and white wire connecting to that little black ball

 

If there is enough slack strip it back just a bit, clean it up and solder.
If not, you'll have to buy a replacement piece.

I suppose you could alway bypass the switch if you don't use it (I never use mine).

 

That whole throttle assembly is roached - I'd replace the whole unit with one from eBay.