Rikuo Motorcycle of the Harley-Davidson, started production in 1929. In 1931 Dabittoson Harley Motorcycle Co., Ltd. was established in Japan. Dabittoson started domestic production of the Harley-Davidson Road King Motorcycle. The 4-cycle, 1200 cc, side-valve V-twin engine produces 28 horsepower for a top speed of 97 km per hour. The Road King motorcycle was improved and produced by Lin Ritsukawa, and Tsui Meguro under the Tokyu Kogyo Kurogane Company during World War II. This included the Type 97 military motorcycle which was often produced with a sidecar, called they Harley-Davidson, through the efforts of Alfred Rich Child, shipped tooling and personnel to
Motorcycle engine systems, was a significant factor in forcing the redesign. Traditionally, engines and gearboxes had separate lubrication systems with different grades of oil; but modern practice is to use the same oil for both. The majority of motorcycle engines are configured as singles, parallel twins, triples, fours and sixes; and all these may be inline or transverse. Vee engines include V-twins and V-fours, and horizontally opposed engines include flat-twins, flat-fours and flat-sixes. Wankel engines are either single-rotor or twin-rotor. Bigger bikes tend to have more cylinders for smoothness and increased power. Modern singles range in capacity from 50 cc to 660