Ingition timing is a very precise thing. Just the slightest of turns can knock it by as much as 5-10 degrees either direction. A timing light, even if it is a $15 wally world special is better than nothing.
Run a search for how to set it. For one though - yes you do have the engine running while doing so and two - set the base timing at 10 btdc.
Yes, black smoke does mean you are running rich. However though, if you are puffing black smoke at a standstill/idle or takeing off, then you have a different issue than just simply not getting into closed loop. Check things like fuel pressure (around 39 psi), any codes/ MIL lights, or a fualty/stuck-open injector.