And while ground clearance was excellent, the Vision’s thrift-store suspension gave vague handling. (A dealer reset partially cured Cycle‘s test bike). But the engine was not quite ready for prime time, with a noticeable flat spot in the carburetion at around 4,000rpm, and an idle speed that could vary by 1,000rpm. What could possibly go wrong? Testers who rode the Vision praised its performance and lack of vibration while admiring its nimble steering. So the Vision was a competent, innovative and sprightly motorcycle. Running on distinctive 18-inch alloy wheels with 90/90 and 110/90 tires, the Vision used a telescopic fork at the front with a single disc brake, while the drum-brake rear wheel hung on Yamaha’s “Monocross” swingarm with a single spring/damper unit adjustable for preload.Ĭycle magazine took the Vision to the drag strip, recording 13.0 seconds at 100mph, which compared well with its contemporaries in the 4-cylinder class. Drive to the 5-speed transmission and shaft final drive was by straight-cut gears. Inside was a plain bearing, single crankpin bottom end connected to a pair of 10.5:1 pistons, driving the four overhead cams by left-and-right spur gears and HyVo chains. Absent was any pretense of cooling fins, just clean alloy cases and smooth cylinders. The Vision’s drivetrain created a uniquely new look, suspended from (and forming an integral part of) its triangulated steel tube frame. And to negate the primary vibration inherent in high-revving, narrow vee engines, a single counterbalance shaft was added forward of the crank. To ensure adequate fueling at low revs, the Mikunis featured accelerator pumps, and the cylinder heads included Yamaha’s YICS induction control system, to improve “swirl” in the combustion chambers and promote more efficient combustion. The Vision was all new in concept and execution: Its liquid-cooled, 552cc dual overhead camshaft 8-valve engine was well oversquare at 80mm bore by 50mm stroke, fed by a pair of honking 36mm Mikuni carburetors. Yamaha fired back with the 75-degree Virago 750 and XVR920 then in 1982 came the revolutionary 70-degree V-twin XZ550R Vision. Honda came first with the 80-degree transverse CX500. Why not try a narrow-angle twin - in spite of their association with heavyweight cruisers? Among the options considered was a 90-degree V-twin, employed to such success by Italian manufacturers. So why not try something different? Kawasaki and Suzuki pretty much stayed the course with their UJMs, while Honda and Yamaha tried new ideas. The Big Four found themselves in a standing-quarter-mile shoot-out every year. They were the sliced white bread of their day. In the late 1970s, every Asian bike maker built air-cooled, inline 4-cylinder bikes - lots of them, from 350cc to 1,100cc. Weight/MPG: 462lb curb, half-tank fuel/57mpg (period test)

Yamaha xz 550