KZ440- Carb Float banging

Installed new carb boots on my son's 82 KZ440. Started the bike up and the left carb is making a banging noise. I can feel the float bowl cover and the float is banging inside the carb as the bike idles!

Going to remove the float bowl cover but never heard of a float banging inside the carb??

I'd guess it is the CV carb's vacuum slide pulsing with the engine and not the float, I can't see the float moving that fast nor does it have much mass so I really doubt it but then again strange things can happen!

A little visual.. #16126

Removed the float bowl and everthing inside looks ok. What would make the vaccum piston pulse?

Not too sure about the cause, but you should probably check to be sure the diaphragm isn't damaged and that the spring is in there. Another thing would be if it were way out of sync possibly, never had one that far out but I guess that could attribute to the cause.