In the early-to-mid 70s the likes of Yamaha, Suzuki and Kawasaki were all trying to chase Honda. The CB750 had been launched in 1969 and it was what they would now call a game-changer. It was the writing on the wall for the British bike industry, but it also posed problems for Honda's Japanese competition. They'd all made their names building high-performance, relatively reliable and cheap 2-strokes but US emissions regulations and the 1974 fuel crisis were killing off 2-strokes in the larger capacity segment.

So the various manufacturers came up with different strategies. Kawasaki went for the performance angle with the Z1 and its derivatives. It had more cubes, an extra cam and a massively over-engineered motor, shoved into an unfortunately under-engineered frame. Suzuki tried the GT750 triple and the rotary RE5 for a while, but eventually dropped them for the GS750, which was essentially a smaller clone of the Kawasaki with a slightly better frame.

Yamaha tried to be different. Everything on the triple is an attempt to do something new or innovative, to make something unique in the market. Three cylinders makes the engine narrower and gives it more character. It's got shaft drive, but without the engine-speed main-shaft that causes gearbox clunks on BMWs. It had standard alloy wheels (in Europe and the US), which was pretty new for the time. Three brake discs, again none of the Japanese 750s were doing that. It had self-cancelling indicators, vacuum fuel taps, and it handled quite well too. It was heavier than the competition and a bit down on power (both because of the shaft), but it still drove very well. And the contemporary road testers loved it.

Basically it was different and it was ahead of its time. The fact that some of those innovations didn't work perfectly is neither here nor there. The only reason it didn't sell in big numbers at the time is because the typical 750 buyer just bought a bike on the basis of performance figures.