High Quality Content by WIKIPEDIA articles! The Yamaha DT is a series of mopeds and motorcycles produced by the Yamaha Motor Corporation. MOdels in the DT series feature an engine displacement of 50 to 400 cc (3.1 to 24 cu in). THe first DT model, the DT-1, was released in 1968 and quickly sold through its initial 12,000 production run. THe DT series was created by Yamaha in the late 1960s when the United States motorcycle market was down. MArket research by Yamaha indicated that, despite slow motorcycle sales, there was a largely untapped market for off-road motorcycles. AT the time, only a few specialty European manufacturers such as Bultaco and Husqvarna made motorcycles specifically for off-road use. INstead, many owners purchased road motorcycles and modified them for off-road use, typically by raising the muffler. SUch modifications were commonly known as creating scramblers. THe first DT model, the DT-1, was released in late 1967 and quickly sold out. THe DT series, and the DT-1 in particular, have been credited with inventing the trail bike category of motorcycle.