Exhaust Back Pressure

I recently finished rebuilding a 84" panhead with a CV carburetor and stock ignition system of points and condenser. At the time of start up I had a free flowing exhaust system on it. Since then putting on 600 trouble free miles. Over the winter I installed a replica stock exhaust system that is considerably quieter than the previous exhaust set up. As it stands now, it pops when cold, stalls out at a stop and it stubborn to restart when stalled. My question is, do I need to rejet the carb because of the increased back pressure?

Here is some additional information that I left out from my earlier post. The size of the main jet is 180 and the pilot is 46.

Symptoms don't sound like an exhaust problem, more like a carb problem, but not jetting size - more like a vacuum leak or clogged jet. If it sat for a seas0n after 600 good miles, maybe the tank dropped some 30 year old gunk into your carb. Seen that before. Good luck!

Thanks for the reply. It wasn't an intake leak. I checked that with an unlit propane torch. I found some sediment in the flow bowl which took me to the pilot jet and main removal. I got cleaned everything and buttoned up. First kick , no popping. Let it get to temp and shut it down to re-start, one kick. Amazing what a tiny piece of crud can do to ruin the day.