Suzuki 2 Strokes

Hey there, I've been working on an old 1976 Suzuki GT550. The engine is all back together and ready to start however I realized that the wiring to the starter motor has been ripped out of the wiring harness for some reason. Everything else works. I am able to simply attach the wire coming off off the starter to the positive terminal of the battery to spin it, however I am aware this can be dangerous for the motor and the battery. Is there a way I can wire up some kind of fuse and a switch to use the starter without having to buy an entire wiring harness? Any thoughts are appreciated!

It may be that the starter clutch has a problem and the PO decided to make it safe by disconnecting it.

In terms of the wiring, it's short fat wire from battery to solenoid and long fat wire from solenoid to starter motor. On the other side of the solenoid, one wire should go to ground and the other to the push button in the right switch block. So it's switched 12v from the OFF-RUN switch to the starter button (internal to that switch) and from there to the solenoid.

Check the wiring diagram