From Yamaha Wiki
The Yamaha SW396 is a motorcycle produced by Yamaha. The vehicle was first introduced on the United States market in 1970. The Europe market would see this machine as the SW400B Europe in 1972. This machine was the predecessor of the SW 643 and the later SW440.
The Engine of the SW396 and SW400 was an 396 cm² Two-stroke engine with 27 Horsepower at 5500 Rpm.
Engine Twin cylinder 396 cm² two-stroke 5-port
Horsepower 27 hp @ 5500 rpm
Bore & stroke 65 x 59.6 mm
Carburetor Single diaphragm carburetor
Overall length 253 cm
Overall width 93 cm
Overall height 102 cm
Track width 46 cm
Dry weight 172 kg