1980 KZ650 E

I've been rebuilding my first Kawasaki and finished the engine rebuild and put it in, all ready to go, but when I turned the key nothing lit up. I checked the starter relay since the battery is new, and that is broken. I bypassed it to check the starter motor and when I make contact with the positive battery terminal there is a click and many sparks of course. The engine is not turning over though. What could possibly be the reason why that is. And what would be my next course of action.

We can assume the engine can be turned over at the crankshaft by a wrench. i'd start by going over the starter related components and wiring. Maybe check the starter motor itself. Rebuild it.