[1] It was part of Yamaha's early efforts to expand their motorcycle lineup and enter the growing off-road market.
The Yamaha AT1 was available in three different models, each corresponding to the year of production:[1] Each year, the AT1 was also available in the Motocross edition designated by an M. The M models were very similar to the regular models other than a few performance-enhancing features, such as weight reduction, higher compression ratio, tuned exhaust, larger carburettor with 26 mm throttle bore, and tuned gearing ratio.
[1] Some parts, such as fuel tanks, were interchangeable between the AT1 and other Yamaha models of the same era, like the CT1.
[3] Yamaha has continued to support these vintage models by producing replacement parts, such as petcocks, which fit the 1969-1971 AT1 models.
[4] This motorcycle, scooter or moped-related article is a stub.