The rundown. Bought my bike on eBay, pretty clean, running, didn't seam to need any major work. Brought it home where it sat for a few months since I went out of town. Got home, ran it down the street and did fine. Then broke it down for a modest cafe racer build. We installed boxer metals airbox delete, emgo mufflers, euro electric enduralast charging system, and electronic ignition. Now the right cylinder is just dogging. Sputtering, backfiring, can't give it any real throttle without caughing. Stalls out every now and then. Pretty much unridable. We tried new Bosch coils and new plugs and wires to no avail. We Have not messed with carbs yet. Really don't know the history on the bike other than the seller said it was running fine and his daily driver. Perhaps the air box delete with filters an the new mufflers are playing a role? Does anyone have any suggestions what to try next? Thanks all!