1960Mark IX, misfires, backfires, etc when driving after a few minutes

Started By: Preston Garner on 2015-06-27 00:00:00

My 1960 Mark IX will backfire, etc. while driving it after about five minutes. I will start it, no problem. Runs smooth. The starting carb will shut down after a brief warm up. I drive off, get about two blocks and it bucks, back fires, and will cut off. Restart and the same until it has been driven for a while.
Carbs have been rebuilt, but set according to the book.