Hopefully the photo is self-explanatory of what I understand from your info.
i would still prefer to have the earthing point on the frame rather than only on the battery box so would fit a lead to a clean (unpainted) spot on the frame from the existing earthing nut and bolt on the battery box. Particularly because you have removed the box a time or two and you cannot see how good the connection is between the box and the frame. It looks as though the inside of the box has had a rough 'n ready slap of grey paint which led me to suspect that the battery had been overcharging (on 12v ) and leaking battery acid had corroded the inside of the box (and maybe the back as well).
Just a small point and it may be due to the photo but if the black lead coming from what looks like a black plastic fuse holder is the Neg battery lead it looks a bit thin, but O.K. for now.
I'd just fit the new battery (you may need to change the terminals on your battery wires to Lucas/spade type) and see how it goes.
No, it won't be a short affecting the ignition as the magneto is completely self-contained and not connected to any of the bike wiring.The Vandal wrote: ↑Sat Sep 17, 2022 11:35 pm A short is definitely a possibility. My first time riding it it did conk out randomly a couple times. I put it down to my inexperience and I was being distracted by a particularly terrible bmw driver infront of me but it could have been a short.