It will need a 12 volt alternator if it has a 12 volt battery.
When the alternator is installed you can connect the generator wire to the Battery wire on the original voltage regulator and not have to do any rewiring. Just connect the Gen wire that was on the generator to the positive post on the alternator.
Come off the positive side of the battery to the ignition switch and then to the coil from the switch. If it gets hot when turned on you have a dead short in the ignition wire. Either the wrong wire or it is grounded somewhere before it gets to the coil.
You can remove the wire from the coil and then connect a test light from the positive post of the battery and to the coil wire at the ignition switch and it is lights that indicates a dead short in that wire somewhere. That is if you have the right wire connected to the ignition switch and not something that goes somewhere else.