The first is your electric choke. It'll never come off as soon as it should after an hour parking (I assume that's how long you need in the Playboy mansion
), the engine will still be hot and require no choke, but the electric heater element controlling the choke will have cooled off and will take some time to heat up again, and will run too rich in that time. Does your choke get a proper 12V? Most people including me at one point in time have looked around the engine room for a ignition +, and found it at the coil, but often that's only 9V, not enough to let the choke come off fast enough. Also make sure your choke is properly adjusted, as described in my book (sorry) the choke has to be as lean as possible while still providing decent cold starting, trial and error testing needed.Second suggestion if it's only one puff of black smoke, could your fuel bowl needles be leaking slowly? At normal running, the fuel is used faster than the leak introduces it, when stopped it leaks until the pressure in the fuel line is gone.
Thirdly, if it's puffing black smoke all the time (and your mileage suggests it) it's too rich constantly, which the cold engine likes, but the warm engine does not. Full details on how to adjust this in my book (sorry), but also check if power valve is blown or more likely hardened and not functioning right. Easiest way is to press it against another same number power valve, they must move the same.
What I would do first? Write down how the choke is adjusted, move it to totally off, and see if it helps. Let us know...