Stewart won the 2006 FIM Amp'd Mobile World Supercross Championship but lost the AMA title to his rival Ricky Carmichael by just two points. He has taken two wins from Carmichael this summer in Toyota AMA Motocross, but crashes and a mechanical DNF at Southwick have him well out of contention for the outdoor title. James will ride for AMA Team USA for the first time at the Motocross des Nations in three weeks in England.
"James is a phenomenal talent with a tremendous future and I wish he and the entire Stewart family the best always," said Evans. "I am directing my energy into a new project that should be exciting for our sport and I will be sharing more about that soon."