The BMW K1600 has been produced with an inline 6 cylinder engine. It just scrapes in at 100 cubic inches. The BMW K1600GTL and its almost identical twin the K1600GT feature an oil/water-cooled 4-stroke in-line 6-cylinder engine, two overhead camshafts, four valves per cylinder and a cubic capacity of 1,649 cc. The GTL's unlade weight, road ready, fully fuelled is just under 350 Kg - BMW quote this as being 348 Kg.
It is the first six-cylinder inline engine in the history of BMW Motorcycles. The bike is available in a GT, a GTL and also an Exclusive GTL model configuration. A Bagger is coming in 2017.
BMW K1600GTL Six Cylinder