The Yamaha XJ900 was borne of the original Yamaha XJ model motorcycle, the XJ 650, which was the foundation for the entire XJ series.
Yamaha XJ900 31A
In its original incarnation launched in 1983, the XJ900 had an air-cooled, double overhead camshaft, 853 cc 4-stroke, 4-cylinder, 8-valve engine. Originally fitted with a handlebar mounted bikini fairing, its handling came in for criticism. This was quickly replaced with a frame mounted upper fairing and retrofitted to all models. The 1983 XJ900 came with anti-dive front forks, shaft drive and has triple disc brakes (2 front, 1 rear).
A revised version was launched in 1984 and displaced 891 cc. Aside from the engine capacity increase it was equipped with more conventional forks than its predecessor and a belly pan came as standard. The increase in engine capacity meant the carburettors went up from 35 mm to 36 mm. Fuel capacity is 22 litres and the transmission is a 5 speed with a top speed of around 200 km/h. Aside from these changes it was nearly identical to the original and was manufactured until 1994.