Motorcycle Repair: 73 CB350F carbs, air screws, cb350f

Question
Hello. I removed carbs to install rebuild kits. The bike ran ok before but was a bit soggy on bottom end. I cleaned and r&r, main & idle jets, needles, float plugs, air screws & gaskets. I put air screws back equal to position of the previous ones. When I started it, it struggled to life and wouldn't idle. When reved it was puttin out some black smoke.  The bike has less than 9100 og miles. I'm a decent mech.  What should I be looking at?

Answer
Clay,

sounds like too much fuel or not enough
air.

-Are the slides in right? I don't
remember if they can be switched or not,
you might want to check them.

-Is the air filter and air box okay? Not plugged?

-Some carb kits are questionable, sometimes it is good to
compare the old jets to the new, they should be similar size.

-Check the choke.

-Make sure none of the floats are stuck,
tap on the float bowl with a screwdriver
handle to free them up.