Weaver began competing in freestyle while still in high school. He caused a sensation at the 1976 Olympic trials when he pinned his first eight opponents. He eventually ended up as the alternate on the Olympic team. Then just two years out of high school, Weaver finished second at the 1979 world championships in San Diego, California. Prior to his triumph in Los Angeles, Weaver had won six national freestyle championships, two FILA World Cup gold medals, two World Cup silver medals, gold medals in tournaments in Germany, Poland and Cuba and a silver medal at the demand freestyle tournament in Tbilisi.