Yamaha's entry into the very competitive Japanese Motorcycle market was with this German DKW RT125 inspired model. The YA1 had a 123 cc two-stroke engine with 5,6 hp and had already a 4-speed gearbox, while the DKW had a 3-speeder. The weight was only 95 kg, tyre size was 2.75-19. Colour was a nice maroon with creme fueltank sidepanels. Later a slightly larger version with 127 cc was introduced, the YB1.

Yamaha YA1, Feb. '55