This is a long thread. Apologies. I didn't read it all. Still using a capacitor? Not a fan. Especially if your bike is some kinda custom and has excessive vibration. I don't give a shit what the sellers say about rubber mounting or the spring mount for the capacitor. They will fail especially that black one the Bros and Mike sells. Freaking sensitive p.o.s. Fart vibration will cause it yo fail. Haha! More recently I have found the antigravity battery with the right shunt style reg/rec combo is rugged and reliable. The way to go. Expensive, yes but it's likely you'll keep buying caps.
Now on your more recent post. If your getting spark, then it'd be a fuel issue. Be careful testing for spark with a Pamco. I clip a jumper cable to the plug and ground the other end WELL! You will pop that lil transistor. I like to use a timing light to check for spark and it's safe. Do you know how to sync carbs? What kind of exhaust? What kind of air filters. Take a video. Post it here.