 1989 was also the year of his 500cc World Championship debut.In 1990 he raced in four different championships, but the highlight was winning the 250cc World Championship in his first full season on a Team Roberts Yamaha YZR250.In a funny and unusual story happening after his loss at the 1991 American Grand Prix at Laguna Seca, According to Michael Scott, Kocinski was so upset after the loss that he drove away from the track recklessly and refused to pull over when stopped by a policeman; he was arrested and sentenced to community service.