Re: carburator and gas lines
Most likely that is the reason you had to put a new carb kit on your engine.
The black bits are the result of alcohol in the fuel deteriorating the inside of the fuel lines causing them to break pieces off inside.
So the answer is yes, replace them, all of them even the tiny ones. Also if your tank is as old as those lines, replace that as well. Unless you bought the tank this year or last year, I would replace it. New ball also, they can also deteriorate.
Install an inline filter after the gas ball and before the pump.