Harley-Davidson models. In the late summer of 1929, Harley-Davidson introduced its 45 cubic inches (737 cm³) flathead V-Twin to compete with the Indian 101 Scout and the Excelsior Super X. This was the "D" model, produced from 1929 to 1931. Riders of Indian motorcycles derisively referred to this model as the "three cylinder Harley" because the generator was upright and parallel to the front cylinder. The Great Depression began a few months after the introduction of their 45 cubic inch (737 cm³) model. Harley-Davidson's sales fell from 21,000 in 1929 to 3,703 in 1933. Despite this, Harley-Davidson unveiled a new lineup
Harley-Davidson backed by the state and local government along with participating organizations and corporations. Paul Gotthold, Director of Operations for the EPA, congratulated the motor company: Harley-Davidson also purchased most of Castalloy, a South Australian producer of cast motorcycle wheels and hubs. The South Australian government has set forth "protection to the purchaser (Harley-Davidson) against environmental risks". In August 2016 Harley-Davidson settled with the EPA for $12 million, without admitting wrongdoing, over the sale of after-market "super tuners". Super tuners were devices, marketed for competition, which enabled increased performance of Harley-Davidson products. However, the devices also modified the emission control systems,