spittin through carb

Have a question I could use help with. A friend of mine rides a 2003 sportster 1200. He had the SE pipes punched and stage one done at the dealer. He now has a problem with reversion at the carb. Dealer tells him this is normal and happens on most sportsters. His bike spits enough fuel to soak the air filter after only three to four hundred miles. Anyone have this problem and if so what was the fix.
Thanx Deano

maybe the carb

My electra glide would sometimes "sneeze" back through the carb usually when downshifting coming to a stop or upon accelerating after the stop... sometimes bad enough to kill the motor. I sent my stock CV carb off this winter to Dakota Kid Carbs and since its been reworked I have not had it sneeze once in 1500 miles. The throttle response is better, gas mileage is better, and I didn't have to do any jetting myself...I just told him what I was running and he set it up for me...told me in a note not to touch anything until I tried his setup first.