The Honda Valkyrie is a motorcycle that was manufactured by Honda from 1997 to 2003. It was designated GL1500C in the US market and F6C in other markets.

A flat-six engine, also known as a horizontally opposed-six, is a six-cylinder piston engine with three cylinders on each side of a central crankshaft. The most common type of flat-six engine is the boxer-six engine, where each pair of opposed cylinders moves inwards and outwards at the same time. An alternative configuration for flat engines is a 180-degree V engine, where both cylinders move to the right then the left at the same time.