Monster Energy Kawasaki has confirmed Malcolm Stewart as part of its 2027 factory line-up. The American rider will share the new Kawasaki KX450F-SR with Garrett Marchbanks, forming the team’s pairing for the SMX World Championship. The move follows Chase Sexton’s departure from Kawasaki, a mutually agreed split that took effect on October 23.

Sexton’s only season with Kawasaki included two 450SX victories, at Anaheim and Salt Lake City, before a knee injury at Thunder Valley brought his campaign to an end. Stewart and Marchbanks will give Kawasaki its fourth different 450 line-up in four years, placing added importance on building continuity for the next programme.

A return to Kawasaki roots

The signing also has a personal angle for Stewart. He raced with Kawasaki Team Green during his amateur years, but never represented the marque as a professional. His five most recent seasons were spent with Rockstar Energy Husqvarna Factory Racing. Kawasaki is part of his family history as well: his older brother James Stewart Jr. won the 450SX title with the manufacturer in 2007 and completed an unbeaten 2008 Pro Motocross Championship.

Since becoming a full-time rider in the premier class in 2017, Malcolm Stewart has collected one main-event win, eight podiums and 32 top-five results. His first 450SX victory came at Tampa in 2025, the same year he won the King of Paris SX. During 2026, he added one podium and 14 SMX finishes inside the top ten.

Marchbanks will continue with Kawasaki after signing a contract extension. He was named 2026 450SX Rookie of the Year and produced career-best fourth-place overall results at both Thunder Valley and Unadilla. He also recorded five SMX top-five finishes before ending the SMX World Championship sixth in the final standings.

Dan Fahie, Kawasaki Racing Senior Manager, said Stewart brings proven experience and a strong work ethic to the team. Fahie also judged that both riders have the speed and ability to challenge at the front of the 450 Class. The new pairing will first appear for the team on January 9, when the Monster Energy AMA Supercross season opens at Angel Stadium.