Rewiring A 1976 Us Import T140v

Welcome Paul. Bloody good choice of bike that man but then I am a bit biased.

Leave it as Negative Earth. There's a few reasons for this - Standards and convention, most vehicles these days are negative earth. Positive earth tended to corrode the main elements (frame and bodywork) where the wiring was connected while negative earth corrodes the wiring, but we're better at protecting wiring these days. Anodes and cathodes stuff.
I'd rather deal with hardened and snappy wiring in a few tens of years than a rusted out frame.

I'd also suggest you make up your own wiring loom rather than buy a ready made one. The ready made ones are sometimes a bit 'short' and can be a difficult fit.
I find that the less connectors there are, the more faith I have in the wiring doing what it's meant to.

Best of luck and let us see how you progress.

 

I have just rewired my 1976 T140v and I decided to go negative earth because that’s what my tiny brain understands. It was pretty straightforward really, If you go to this page there is a layout for an A65 https://rupesrewires.com/classic-bike-24/
which is pretty much what I used, although I kept the original two-wire alternator. I used an Acewell Speedo/tacho unit too which works well, but mine isn’t standard. Good luck!

 

I actually quite enjoyed doing the rewire, which surprised me as I’m more of a spanner and hammer type of guy

 

@PaulK Nice bike. Have you cleaned the carbs. Quick test just drop a cap of fuel down both bores and try it. Welcome to the family

 

I can definitely endorse what @Iron is advising about polarity and making your own loom having done my Tbird including converting it to 12 volt. The wiring is pretty basic.