The 1990 Yamaha 0WC1 had an upside-down front fork and power was increased to 155 ps. Wayne Rainey won 7 races with it and scored his first World Championship. Yamaha again won the Manufacturers World Championship, now for the 6th time. The 0WC1 motor was also later the basis engine which Yamaha made available for customers, as in the ROC bikes.

Yamaha 0WC1, 1990