Not-many people recall that at one time, before Suzuki released their rotary-engined bike, Yamaha was getting significant publicity for their rotary design.
It came very-close to production, and a couple of the things that helped to prevent its sales were the Arab oil embargo, and the growing influence of the EPA for emissions standards. Because rotaries were not fuel 'sippers' but rather 'guzzlers,' and at the time were 'dirty' in emissions, Yamaha decided to withhold the bike from the market. They had running prototypes, and had production tooling underway when the decision was rendered. Thos who rode the prototypes say they were powerful and smooth in operation. Yamaha also overcame one of the 'knocks' against rotary engines, that they were ugly. While the Yamaha isn't beautiful, I think theirs is better-looking than the Suzuki (we won't bother bringing-up the Giugiaro-designed first-year Suzuki round, cylindrical, green plastic-covered instrument pod and its companion rear taillight, also a round cylinder, other than-to mention it here), which was often described as 'industrial-looking,' like a stationary powerplant.
It came very-close to production, and a couple of the things that helped to prevent its sales were the Arab oil embargo, and the growing influence of the EPA for emissions standards. Because rotaries were not fuel 'sippers' but rather 'guzzlers,' and at the time were 'dirty' in emissions, Yamaha decided to withhold the bike from the market. They had running prototypes, and had production tooling underway when the decision was rendered. Thos who rode the prototypes say they were powerful and smooth in operation. Yamaha also overcame one of the 'knocks' against rotary engines, that they were ugly. While the Yamaha isn't beautiful, I think theirs is better-looking than the Suzuki (we won't bother bringing-up the Giugiaro-designed first-year Suzuki round, cylindrical, green plastic-covered instrument pod and its companion rear taillight, also a round cylinder, other than-to mention it here), which was often described as 'industrial-looking,' like a stationary powerplant.