All YAMAHA FS-1 models and generations by year, specs reference and pictures - autoevolution
Yamaha V50 (motorcycle) - Wikipedia
Yamaha TY 50 1975 Motorcycle Photos and Specs
Aquad Yamaha - Mobility - 1975 Yamaha TY50 This was the 50cc model of the TY series of street-legal trial machines. The specs on the off-road bike-specific single-cylinder engine with a piston