The YG1 was positioned between the failing MF1 and SC1 models and actually "rescued" Yamaha financially. It had been designed already a year earlier and the new President, Mr. Koike, grabbed it and brought it into production. It was an instant success worldwide and sold in the thousands for many years. The second picture shows the YG1D from Apr. '64 which was the first "Autolube" model. Length was 1815 mm, wheelbase 1145 nn, weight 70 kg and the 73 cc rotary valve engine developed a healthy 6.5 hp @ 7000 rpm. It had a 4-speed gearbox. Picture 3 is the YF1, a 50 cc version of the YG1 (Apr. '64), with the leading link forks of the old MF1.

Yamaha YG1, Mar. '63