2015 HARLEY-DAVIDSON FLHTCUL Fuelpropulsion System Problems

I PURCHASED A 2015 ULTRA CLASSIC LOW IN JUNE 2015 A GREAT MACHINE AND ABOUT 4500 MILES ON IT ALREADY BUT I HAVE A PROBLEM WITH IT. WHEN I TAKE OFF FROM A STOP AT AN INTERSECTION OR TRAFFIC LIGHT THE ENGINE STUMBLES AND KNOCKS, SORT OF LIKE WHEN YOU TRY TO TAKE OFF IN 2ND GEAR. I HAVE TAKEN IT TO ADIRONDACK HARLEY-DAVIDSON 106 BELLEN RD, BROADALBIN, NY 12025 AND JOE'S MOTORCYCLE REPAIR, DYNO TUNING, DYNO PERFORMANCE, 124 N CENTRAL AVE, MECHANICVILLE, NY 12118 TO HAVE THIS PROBLEM CORRECTED. I WAS TOLD BY BOTH PLACES THAT THE REASON THE MOTORCYCLE DOES THAT IS THAT THE FUEL PROGRAMMING IS SET TOO LEAN TO MEET HARLEY-DAVIDSON'S REQUIREMENT TO MEET GOVERNMENT EPA STANDARDS. I WAS TOLD BY BOTH, ADIRONDACK HARLEY-DAVIDSON AND JOE'S MOTORCYCLE REPAIR, THAT THEY CAN FIX THE PROBLEM BY INSTALLING HARLEY-DAVIDSON SCREAMING EAGLE PERFORMANCE PARTS: 1.FUEL TUNER 2. HIGH FLOW...