2017 Harley-Davidson® Fat Boy® The original fat custom icon matches unmistakable style with a High Output Twin Cam 103B™ engine. Sometimes something comes along that changes everything. When Willie G. Davidson rode the Fat Boy® model into Daytona Bike Week the 1st time, it stopped traffic. In the years since, the Fat Boy hasn’t let up. From the chrome solid disc wheels, to the muscular lines of the High Output Twin Cam 103B™ engine, to the curve of its distinctive rear fender, this machine is built to make an impact. Ride 1 and you’ll understand.