For the present time forget the smoke...
get it to start, full choke if necessary...then
sequentially less choke, while using the throttle to keep RPM up... don't just immediately turn the choke off and expect it to idle...you haven't even done a final set on that yet!
The plugs may be on the verge of fouling (too much fuel)? Have you inspected or replaced the spark plugs?
Alternately, try a start attempt using FULL throttle/NO choke (it'll clear fuel from the chambers) ....be prepared to back off the throttle. (or the tach needle will fly off)
You didn't overcompensate, turning throttle adjuster up too much during prior start attempts, didja?
"Dumcatiman"