Should we include the Benelli 6-pot Motorbike in this Forum ? I heard it's 6 cylinder motor is very smooth running. Quote my mate Wikipedia: The Benelli Sei is a series of motorcycles that were produced by Italian manufacturer Benelli, and masterminded by automotive designer Alejandro de Tomaso, from 1973 to 1989.[2] Two models were made, with 750 and 900 cc displacement. The 750 was the first production motorcycle with a six-cylinder engine.