The choke probably needs adjusting. I'd also look at the accelerator pump shot. "New" or "rebuilt" doesn't equate to "good". Also have a look at the initial timing.
The choke is correctly adjusted, the only way it runs right when cold is if the choke is slightly closed. This is a manual choke. the accelerator pump is fine so far as I can tell. My timing is good according to my light. Thanks for the reply