CarBrandLogos archive · Yamaha · 1973

YamahaRD350

Reed valves, 347cc and a habit of embarrassing much larger machinery.

Photo: John Goetzinger · CC BY-SA 2.0

The story

A defining chapter in Yamaha history.

Explore the ideas, engineering and context that shaped the Yamaha RD350, then continue into its specifications and place in the marque's lineage.

Origins

The RD350 arrived in 1973 as the development of Yamaha's R5, and the letters stood for Race Developed — a claim the company could actually support, because the reed-valve induction and porting came directly from its Grand Prix two-stroke programme. The engine was a 347cc air-cooled two-stroke parallel twin, fed through reeds that improved low-speed running without blunting the top end, and it drove through a six-speed gearbox.

1973 Yamaha RD350 · John Goetzinger · CC BY-SA 2.0

Design and engineering

What made the bike notorious was its power-to-weight ratio. It was light, and once the engine came onto the pipe the acceleration was out of all proportion to the capacity, which meant an RD350 could see off far bigger four-strokes on a twisting road in the hands of someone who could keep it in its narrow powerband. It was equally capable of catching out anyone who could not, and it acquired a reputation among insurers and parents to match.

In production

It was also the club racer's default choice, cheap enough to buy and tune and closely enough related to Yamaha's racing machinery that parts and knowledge were everywhere. That fed a whole generation of riders into competition.

Legacy

The RD400 replaced it in 1976, and tightening emissions rules eventually ended the road-going two-stroke sports bike altogether. A version built under licence in India by Escorts kept the name alive for years afterwards and became a cult machine there in its own right, remembered for exactly the same reasons.

At a glance