Thanks TerryM... This is my train of thought, but needed someone else to confirm

I'll hook up the battery and run the bike, see what volts I get then... Was a bit concerned that the previous owner may have converted to 12v

If its got a 12 volt winding, don't try and regulate it to 6 volts, it will likely burn out.

I’ve got a 71’ CT1 175 and plan to hook up a regulator rectifier. Did you ever post that pic? I’m certain my bike doesn’t have one stock but would love to see your wiring with the yellow/white wire. Thanks!

Sorry we don't have the wiring diagram for your bike.

Generally if the generator is so low output not to have been fitted with a regulator, fitting one will reduce the output to nearly nothing.