Fenderfreek, fenderfreek@lemmy.world

That’s great! Hopefully it continues to behave for you - I rescued an ‘87 750 Virago many years ago, and it was a quirky bike to get tuned properly, but a neat little project.

Try this link for a wiring diagram:

https://drive.google.com/drive/u/0/mobile/folders/13TttlH9fJnzFSQlDkB-GYDEXsNu7FPoe?usp=sharing

That looks like exactly what happens when a connector has too much current passed through it, and it is not uncommon for motorcycles to suffer this kind of failure from loose/corroded connections. Unless you grounded your welder to one of those components instead of part of the frame near your weld, though, there’s no path for electricity through there from a welder. I still suspect you coincidentally found an existing problem, but fortunately all of those components can be fairly easily checked with a multimeter. Start eliminating possibilities with a wiring diagram for your bike, and a service manual, if you can find one.

Not related to welding on the frame, no current goes through the part in question. Either something got damaged moving stuff around or there’s a bad/disconnected part of the electrical system. Check a wiring diagram for things like kickstand switch, kill switch, etc. These can cut spark. Also check all your grounds and weatherproof connectors.