Jack Young started racing bikes with younger brother Frank on the Sand Pits at Findon in Adelaide, before starting his speedway career at the Kilburn Speedway on 9 May 1947 riding a 1926 Harley-Davidson Peashooter borrowed from his brother. There he rode alongside older brother Wally "Joey" Young (b. 1916 – d. 1990), and younger brother Frank. Jack and Frank both represented Australia in test matches against England. Quickly proving himself to be one of the best riders in Adelaide, Jack placed an impressive second in the SA title in 1947 (after only having raced at a couple of meetings), and would win his first South Australian Championship in 1948. He would go on to win the SA Championship again in 1954, 1955, 1956, 1958, 1959, 1960, 1963 and 1964, all at Rowley Park Speedway. Young would win the Queensland State Championship in 1953 at the Brisbane Exhibition Ground, and the Victorian State Championship in 1957 at the Tracey's Speedway in Melbourne.