2 stroke not starting

Goudy

It's difficult to tell without seeing it, but it being blocked up by this black stuff won't help.

Stale fuel in carbs usually leaves a green or tanny coloured hard furry or scale substance that can be hard to shift.
This black stuff may be sealant someone has used in the past to botch a repair, as it's common for the carbs to block up when left idle for a while it has no doubt been apart before.

As they don't sit level like a car or motorbike carb there is no float in them, they use a diaphragm that allows the carb to draw fuel into it when the pressure drops on one side, this will no doubt work against the sprung ball that acts as a inlet valve. (pushing the primer blub over rides the diaphragm to prime the bowl).

If all that is intact, not blocked and the diaphragm is not split and the bowl is sealed, that should work.

The hole to the venturi is the jet, again it shouldn't be blocked and there shouldn't be anything in the bowl or tank to block it.

If you can identify the model and carb, you can buy a rebuild kit for a few quid that should come with new gaskets, seals and wearable parts or see if you can find a new carb, there's some carbs on Amazon for as little as £13.99.