TWO TAKES ON A big single
There’s no doubt that Yamaha’s retro racer SR500, introduced in 1978, was a bold move, and after an initial wave of nostalgia-fuelled buying, sales tapered away rapidly. After all, it was slow, difficult to start, and, in an era of multi-cylinder rocket ships, more than somewhat of an anachronism. Yamaha was chastened, but not completely discouraged with the overall concept; perhaps all that was needed was a re-think. A major re-think. What happened eight years after the SR500’s debut was a motorcycle that owed just one thing to its predecessor – the fact that it was a single cylinder four-stroke.
Gone completely was the salute to the British singles of yore. The new machine – dubbed SRX600 – was a whole new slant on the big single. Beginning with the powerplant, here was a 608cc, single overhead cam, four-valve donk that had its origins in the on/off-road XT600E (with 1mm smaller bore to produce 595cc), with more power (although still not of the neck-snapping variety), a gear-driven balance shaft, CDI ignition, two-stage carburettor, and very nice five-speed gearbox with a light, responsive clutch. Basically taken from the XT600 set up, the ‘dual’ carburetion saw one, slide-operated carburettor body directing mixture to one of the inlet valves for low rev running, after which the second, constant velocity carb kicks in, feeding the second inlet valve. Although slightly up-spec from the XT600 engine,
