Wont start after coil replacement
I purchased a used mower (craftsman ltx1000). It has a 20hp briggs and stratton motor (407777-0121 E5 - i believe). The motor only had spark in one of two cylinders and was only running on one. I replaced the coils and rebuilt the carb while i was at it. I have gapped the coils at .012 and the carb seems to be supplying fuel. Now it wont start. I do seem to be getting afterfires with the choke closed and little pops of fire out the air intake with the choke open. I am assuming it is a timing issue, but i am unsure where to go with it next. Any help would be appreciated. I am not new to motors, but not all that accomplished either. Please keep that in mind if you offer advice or explanations. Thanks in advance.