Motorcycle Repair: 1999 Heritage, Backfire etc., intermediate jet, mike bike

Question
QUESTION: Mike,

Bike has progressively become harder to start (when cold). Pops, backfires etc. Once warmed it is better, but not good. Flat spot when twisting throttle. Bike is running S&S Super E. Carb was dialed in (perfectly) a few months ago. Not sure where to turn regarding this one. Air leak? Accelerator pump? Coils? Exhaust Gaskets? All of the above? Bike has 98k on engine. To my knowledge, Carb has NEVER been rebuilt.

ANSWER: pull your plugs and let me know what color they are
Mike

---------- FOLLOW-UP ----------

QUESTION: Put new plugs in. Old ones were Brown/Black in color. New plugs (obviously) did not help. Gap is correct etc.

Answer
If you have adjustable pushrods, make sure they are not to tight. Check for a air leak at the intake. You can warm the bike up and with some carb cleaner, spray a little around the intake. If your RPMs go up you have a leak. Lastly, remove the bowl on the carb and check the intermediate jet to see if has a speck of dirt in it
Good luck and happy riding
Mike