3. Single


The single-cylinder engine has probably powered more motorcycles – street and dirt – than any other engine configuration. Early on, the Single was the most uncomplicated engine to produce and maintain, and it still is. While use of Singles has waned in popularity among street bikes, modern dirt bikes all utilize single-cylinder engines. Some noted modern street bike exceptions include KTM’s 390 and 690 Dukes, Suzuki’s Boulevard S40, and Yamaha’s SR400. Most scooters also utilize single-cylinder engines.