DCOE strange issue

[InAccordance]

Have had twin 45s running for almost 3 years now with no major issues outside of them being nitpicky with temperatures and having to fine tune them but here in the past couple of months, something strange has been going on.
I can start it up from cold and after it warms up a bit, engine runs great, carbs do just fine and sing right along.
Now the odd issue is if I stop somewhere and if the car sits for more than 10 minutes, when I go to take off again, it runs like absolute dogshit. Bogging, falling on its face, hesitating under light throttle, idles slightly higher (about 100 to 200 rpm higher than normal). I have to be extra careful when starting from a stop because if I dont rev it high enough, it will almost die when letting the clutch out. You can imagine how dangerous it can be if trying to enter traffic and such. After a second, it kicks right back up and is ok, still bogging and hesitating under light throttle though.
Now that being said, If I rail on it for 5 minutes or so, it goes right back to normal and runs great again, which is what I tend to do since I've gotten used to this happening.
Any ideas on what could be causing something like this to happen?

I do shoot carb cleaner though them once a month and have taken the tops off to see if maybe there is debris in there but haven't found anything so far.
Gone through and checked for vacuum leaks around the intake on either side and haven't found anything yet.

[ShiRen]

Vapor lock? Make sure the fuel lines are not touching anything hot and maybe insulate them. Your coolant temps good?

Only other thing I would think of is giving the carbs an ultrasonic clean.

[2oodoor]

Iwonder if its hot soaking, gas dripping into manifold ?
Chexk coil connections, sounds like bad coil but with the info you providing.
Do you think its starving for fuel or too much?

[2oodoor]

I have counted turns in for idle "mix" screws, then take them out and shoot brake clean in hole then return the screws.
Check throttle shafts for binding, excess shaft "wobble" ie intetmitant vacuum leaks.

[InAccordance]

If anything it runs rich. I'd did see a puff of black smoke after restarting it the other day. I have the hood off for some other work and it poofed out of where the header connects together (it's a 2 piece so it leaks normally)
It does have worn valve guides so it always poofs a bit of smoke on startup when hot or cold but that was the 1st time I've noticed black smoke

[ShiRen]

Pressurized tank blowing passed the needle and seat?

[InAccordance]

Pressurized tank blowing passed the needle and seat?

I'll have to test that, It does always have pressure built up and hisses out when you take the gas cap off.

[ShiRen]

I think when the vacuum lines are deleted many of us do a no no and block off the vent line... or its just collapsed with age. It would be wise, whether that is the problem or not, to run a new vent line off the tank, even if it is vent to atmosphere.