Yamaha began competing internationally in 1956 when they entered the Catalina Grand Prix, again with the YA-1, at which they placed sixth. The YA-1 was followed by the YA-2 of 1957, another 125cc two stroke, but with significantly improved frame and suspension. The YD-1 of 1957 was a 250cc two-stroke twin cylinder motorcycle, resembling the YA-2, but with a larger and more powerful motor. A performance version of this bike, the YDS-1 housed the 250cc two-stroke twin in a double downtube cradle frame and offered the first five-speed transmission in a Japanese motorcycle. This period also saw Yamaha offer its first outboard marine engine.