Rewrite of all symptoms....PLEASE HELP

1. Bike starts fine
2. With choke pulled out the bike hiccups like there is a vacuum leak somewhere. When it does this fuel drips from the plunger of the choke where it enters the left carb.
3. Once warmed up the bike idles with some hiccup.
4. When trhottle is engaged to rev the bike the LEFT cylinder will backfire and a few times it has cause a flame backfire out of the left pipe.
5. When riding the bike it is hard to get moving in first gear because the left cylinder cuts in and out. Once moving the bike will surge because of the left cylinder cutting in and out. Once at a higher speed it will level out and run....until you disengage the throttle. When you roll on the throttle again it will cut in and out again.

Other info:
Stock Carbs-No jetting
AI still on the bike


2003 Red and Black Speedy. What do I want to change on my bike next????