Uncini was born at Recanati, province of Macerata. He made his debut as professional motorcycle road racer in the 750cc class with Laverda, moving later to Ducati, with whom he earned various titles as Italian champion. His first year in the Grand Prix World Championship was with Yamaha in 1976, in both the 250cc and the 350cc classes. The following year he continued to race in both classes, this time with the Harley-Davidson team, winning two Grands Prix in 250cc (Grand Prix of Nations and Czechoslovakia) and finishing second in championship behind Mario Lega. However, his quarrelsome relationship with teammate Walter Villa forced him to move back to Yamaha.

After some disappointing years with a privateer Yamaha team, in 1979 he bought a Suzuki and launched a private team of his own in the 500cc class. He was the top-ranking privateer both in 1979 and 1980, with 5th- and 4th-place finishes. Accidents hindered his 1981 season, but after Marco Lucchinelli left Suzuki to join Honda, Suzuki offered Uncini an official factory-sponsored race bike run by Roberto Gallina's team. Finally, with a competitive vehicle, Uncini won the World Championship in 1982, scoring five victories (GPs of Austria, Netherlands, Yugoslavia, Great Britain and GP of Nations). He was the last Italian rider to win the 500cc crown until Valentino Rossi won in 2001.

...
Wikipedia