Be sure your "starter valve" (part number 27583-88, #48 in linked exploded view below) is fully seating. There is no "choke" on those carbs. A choke is a butterfly mounted in the front of the venturi. Those went away with the switch to CV carbs.

Exploded view of your carb: http://partsfinder.onlinemicrofiche....TOR%20ASSEMBLY

Chokes don't leak but enrichers can, and if they are pulled slightly off the seat can mimic flooding. The black viton sealing area on the starter valve can wear too. I inspect those using a bright light. As mentioned above vacuum fuel valves can malfunction. If their diaphragm pinholes it can pass fuel straight to the engine. (That's one reason I get rid of them on my personal bikes.)