When have you replaced all the fuel lines.... fuel filters?
I suggest starting with a portable tank and see what happens....otherwise boil it out and use OEM parts.
No OLD gray fuel line and no wing nuts.
Going old school on you!
I think your carbs should be boiled in a ultrasonic mechanical cleaning machine. And then go through it.
What you describe is exactly true. Falls on its face when you go to hit it. Lean situation.
Probably not good for it at all.
Certainly lots of good info here, did you use OEM parts on the carb in the beginning? Welch plugs are easy in my mind...I use I drip of lock tight sealer.
To many compression tests and to much writing, not enough diagnosing.
Work until it's fixed.
What happens when you pump the primer ball?
Probably would have ran some chemicals through it but since you snapped the bolts you have your work cut out for you. I'm also in bracket water and I always heat the crap out of them...and when I say "Hot" I mean hot.
Then I use children's crayons on them.
Best way to get yours off is to weld...