1984 FJ/YX600

[kiwi5000]

So I purchased this project bike for the sake of learning how to work on a bike and not feel like if i screw it up then it's not a big deal. This is my 1984 FJ600 with a 1986 YX600 motor or frankenbike as I like to call it. I've sorted out some of the wiring (some of it's still finicky though) and was able to get it to kick over but now I'm at a stand still. New plugs. Changed the oil and filter. I sprayed the carbs with cleaner but not entirely sure it's 100% so I might just buy all new jets and take it apart and soak it. Before I go further though I'd like to share my troubles with anyone who could help.

1.) After testing the spark, there was a residual power surge. Yeah I got a little shock. I did it again (without holding it) and saw a residual spark. Like it's hold the current temporary then letting it go. Is that normal?
2.) An odd thing happened when i was turning it over after I let go of the switch it kept turning! I pushed the kill switch and shut the ignition off but it was still turning over! Is that normal? Ok, I know it's not normal but what's the deal with that? It was scary.
3.) It backfires out the muffler when I turn it over. Occasionally. Someone told me it was timing and I've ordered an ignition box just to test that. I'm leaning towards the carbs.
4.) When I turn it over one of the carbs looks like it's shooting out the gas. Like a mist. What could cause that?

That's all for now. I'm just trying to get it running and it's fighting me somethin fierce. Thank you for your time. I'll be updating this when I can.