Backfiring out carb and wont run right

Couple more pennnies...I don't have a choke and have to run for about 90 seconds to idle down. It then gets crisp on the throttle. I am at 24 initial on timing, but pretty hefty bump stick, .614 with 256 @ .050. If you don't find a vacuum problem, advanced your initial to where your starter is just starting to slow turn, then tweak it back about a degree or two, you should be in the park. Just remember, you don't want to end up with too much total advance, somewhere in the 32-36 degrees range.