Sooty carb/throttle body

[triumph]

Hi all,
My van has a 2.3l air cooled injected engine from stateside tuning, came with the van.

Sometimes the van runs a little “lumpy”.

I took the air filters off- and there was some petrol loose on top of both carbs!?
There is a balancing tube between the filters, could this spread petrol around?

Also, one single carb body was black/sooty. Pulled this and the cylinder next to its plugs, Both looked fairly similar - a bit sooty!

Where should I go from here?