2005 Byrne raced a limited AMA 250cc Supercross season, but earned a podium finish at the Feb. 5th Anaheim, Calif., round... He contested the AMA 250cc Motocross Championship, earning overall top-fives at Binghamton, N.Y., and San Bernardino, Calif... Raced with Kawasaki Motocross.

2004 Byrne earned top-five finishes in the AMA 250cc Supercross races at Anaheim (Jan. 3) and San Diego, Calif.... He raced in the AMA 250cc Motocross Championship, earning two more overall top-five finishes... Raced with Team Chevy Trucks Kawasaki.

2003 Byrne raced a limited AMA 250cc Supercross season, but advanced through the ranks to fourth-place finishes at Anaheim, and San Diego, Calif... He raced the AMA 125cc U.S. Motocross Championship, taking overall podium finishes at Southwick, Mass., and Washougal, Wash... Raced with Amsoil Honda team.