A spark plug is a device that delivers electric current from the ignition to the combustion chamber of an engine to ignite the compressed mixture of air and fuel. All motorcycles, including those from ...

It’s not every day that Harley-Davidson comes out with a new engine. In fact, over the course of its 113-year history, it has only produced eight iterations of its Big Twin engines. And now it has ...

Harley-Davidson's Big Twin is the heart and soul of America's most famous touring bikes. As Cycle World put it: "If ever an engine inspired religious fervor, this is it." This fall the icon gets an ...

MILWAUKEE — Harley-Davidson Inc. on Tuesday introduced an all-new engine, the Milwaukee-Eight, named for the city where the company was born. Harley says it's only the eighth time in the company's 113 ...