On the 84 I had, I ended cutting and splicing in a used MJ50 ignition key switch into the harness. Mine was three position, though. Different wires soldered to the contacts on the original. I could not find on a generic one with the same. The brown is turn signal/horn , grey is oil light, if I remember right. Red and black with red stipe wires are your start circuit, black is ground.
Make sure to get a 6v relay. I had to hunt for awhile find any yamaha switch (qt50/mj50/whatever else) that was similar.
If anything, you can try pushing out the pins of the female connector and rearrange them in the correct order to match your new switch. May or may not work, but that saves you from have to splice.