Reinstalled stock carbs after cleaning, now engine dies when given throttle

So I recently repaired the ignition system on this my 78' Kz650b-2 and finally got it sparking & starting up with the push start. However the only way I could get it to initially start was spraying gasoline directly in the carburetor with a spray bottle through the air intake manifolds, it now starts and idles at a decent range after adjusting the idle screw on the top of the carb. The only issue now is that when I turn the throttle too sharply the engine dies, it accelerates slightly but when the throttle is turned even slightly too much it dies. I cleaned the carbs out already and all the float needles looked fine as well so im not sure where to start looking in terms of fixing this.

Occasionally when the bike is on its side stand the overflow hole on the far left carb will empty out a little gas but only from that one overflow point. The manifolds are a little cracked but I tested them out by spraying wd-40 in there with the engine on and nothing happened so I assume the seal is fine still. Any ideas? This forum has helped immensely in getting this bike working so im turning to y'all once again!

I'd replace those carb boots straight away. Cracks are BAD, even if they pass the WD-40 test. That test only shows gross leaks anyway, not smaller leaks. Not to mention if the boots are not leaking now they will be soon.

Checking fuel level in the carbs as described in the factory service manual is an important test. You can pencil point sharpen some vinyl tubing and screw them into the float bowl drain screw threads to make a cheap tool. Most likely the float needles are weak or dirty causing a high fuel level which can lead to overflowing.

Regarding the engine not accepting throttle is concerned, are you running the stock airbox? If not the carbs will need rejetting. Also, make sure all the bikes other maintenance is up to date such as valve adjustment and points clean/gaping. You can't diagnose a bike running problem unless all the maintenance is up to date.

Regarding cutting out when the throttles opened. How fast is fast when opening? If it cuts out when the throttle is opened from idle to full open in an instant then it will cut out.
Its carburated not injected. Opening the throttle that quickly opens the slide, therefore the airflow, before the vacuum can suck the fuel through the jets therefore resulting in the mixture being too lean to burn. It'll be even worse with a quick action throttle.

First step is as Nessism suggests, replace those carb rubbers.

So as for the airbox I do not have the stock option but rather 4 metal pod filters if you are familiar with that. They were on the bike when I got it. In terms of other maintenance the bike is on point in terms of the points/gap (points are new and gapped as well as timing set) as for the valve adjustment, I am not privy to that process yet.

To answer Warren's question about the throttle, If I turn the throttle at idle without doing so very slowly and steadily the bike engine will die. If I turn the throttle very slowly it will accelerate to about 2000 rpm's before it starts to sputter a bit and seems to want to die if I continue accelerating. If I turn the choke on when the bike starts it usually goes up to 4000 rpm's before it starts to idle and the bike throttle action at higher rpms is totally normally and doesn't want to die out. When I turn the choke off that is when the issue starts.

Regardless I just order some new carb manifold boots to hopefully help the issue a little

If it runs better with the choke that suggests it's starved for gas under normal conditions. You should check your pilot fuel circuits to ensure they are clean and operable. It's the pilot circuits that deliver fuel to the engine up to about 3000 rpm.