Kohler m16s carb issue

I have a Kohler m16s on a giant vac leaf loader and lately all it wants to do is run on choke only and dies right after the choke is released. So I replaced it with a aftermarket one from a dealer and it still does the same thing. Even with a new fuel filter, lines, and plug. The plug is black and sooty.

Could the mechanical fuel pump be bad? I did have it out for Abit for some work in that area before.
Also, with the fuel line unhooked from the filter, shouldn't the pump be sucking my...

Kohler m16s carb issue