1982 Yamaha XJ650 LJ Turbo Motorcycle

Description

In the early 1980s the big four Japanese motorcycle companies each added a turbocharged bike to their model line-up, as forced induction technology became a big marketing tool. The second to arrive after Honda’s CX500 Turbo, Yamaha’s XJ650LJ combined futuristic, sharply angular styling with an air-cooled in-line four-cylinder engine instead of the V-twin configuration favoured by their rivals.  Based on Yamaha’s standard XJ650, already regarded as one of the finest handling 4-strokes of the era, the Turbo was similarly shaft driven and featured effective twin discs braking up front and a drum at the rear.  Mounted in the space between the XJ650’s transmission and rear wheel, the turbocharger was a diminutive Mitsubishi unit with an exhaust wheel of just 39mm diameter, limited to 7.7 pounds per square inch via a boost pressure-controlled exhaust wastegate.  Due to the turbo’s location, Yamaha had to make do with old school fuel delivery instead of fuel injection, using four Mikuni 30mm carburettors, while the XJ650 engine’s bottom end, pistons, clutch and transmission were all strengthened to cope with the additional power.  Known as the Seca for the American market, the turbocharged Yamaha’s power delivery was seamless by the standards of the day, transforming itself into a superbike once full boost arrived at 6,500rpm.  A supremely comfortable sports touring bike thanks to the wind protection afforded by that radical fairing, Yamaha uprated the XJ650’s suspension from the standard naturally-aspirated version, adding an air-adjustable function to the front fork.  Another novel feature, Yamaha claimed the title of the world’s first electronic on-board diagnosis system, an LCD display checking on battery, brake fluid, engine oil, side stand position and lights. Prohibitively expensive, the turbo XJ650 was roughly twice the price of the standard model, so it’s hardly surprising Yamaha sold only limited numbers, particularly here in Australia.