The Sportster comes to life via an air-cooled, 45° inclined V-twin 4-stroke Evolution® mill with an OHV-pushrod design. Compression ratio is 9.7:1, while bore-stroke ratio is 88.85 x 96.82 mm (3.50 x 3.81 inches). The most distinct feature of the ’06 Sportsters are their chunkier dual seats and flatter but still peanut-shaped “Custom” tank.
