Bike making a sputtering sound with choke on halfway.

[bergstrom25]

Just put on a new petcock and fuel hose, cleaned carb, and new spark plug.

When I start the bike cold I switch it to prime, do I need the choke on full when it's cold? When I let it warm it, I pull it the choke back to about half and the bike makes this sort of sputter sound. Once its warmed up I let off the choke and after a while it runs fine, just wondering why it sputters. Kind of sounds like it's not getting enough fuel. This is my first bike, a 2006, so I'm very new to all this. Any help would be much appreciated!