TOPIC:

Got a 77 Z650 with the ancient rectifier and regulator. The black/yellow wire from the rectifier has had the insulation partly burnt off it, and the battery goes flat over the period of a day. This has only started happening very recently, shortly after the black/yellow wire melted.
I've read through the other posts here, and was after suggestions on the best rectifier and regulator, plus any wiring mods I should do, for this bike.

Regards, Andrew.

You could change the charging system out with a later 650 that has the reg/rec combo. On the 77 650's both the reg and rec have to be working in tip top condishion or one will take out the other .
Mark

Make sure you wiring is in good shape. Pass current backward through a rectifier and it burns out instantly. Which is why you put the positive wire on battery first. With ground not connected there is no circuit at all. Dead shorts reek havoc on rectifiers.