In 2002, the YZR-M1 was introduced alongside 500cc two-strokes, featuring an inline-4 engine designed to balance power with the handling characteristics of the previous YZR500. The M1’s engine initially displaced 942 cc, progressing to the full 990 cc limit during the season, and incorporated an electronic engine management system to manage four-stroke engine braking. Max Biaggi, John Kocinski, Norihiko Fujiwara and Kyoji Namba test-rode and developed the bike throughout 2001. In its debut racing season, ridden by Biaggi and Carlos Checa, the M1 achieved two wins and secured second place in both the Riders’ and Manufacturers’ Championships.
The 2003 season saw the engine switch to fuel injection, and the engine brake control system was replaced with an Idle Control System intended to improve stability during deceleration. Riders Checa, Alex Barros, Olivier Jacque, Marco Melandri, Shinya Nakano and Norifumi Abe piloted the M1, but the season yielded no wins, and Yamaha finished third in the Manufacturers’ Championship.
Valentino Rossi joined Yamaha in 2004, prompting questions about the M1’s ability to compete with the dominant Honda RC211V. Yamaha responded with an accelerated development program, and Rossi brought with him crew chief Jeremy Burgess and his team. Engineers transitioned to a four-valve cylinder head and a revised “long-bang” cylinder firing order – 270°-180°-90°-180° – designed to mimic the kinetic energy of a V4 engine. The updated M1 secured its debut race win at Welkom, South Africa, and ultimately claimed nine victories, delivering Rossi the Riders’ Championship.
The partnership between Rossi and the YZR-M1 continued to prove successful in 2005, with Rossi winning the Championship by a 147-point margin. The 2005 M1 was considered by insiders to be a particularly strong race bike, and Rossi himself later described it as the greatest bike he had ever ridden.
The 2006 season presented challenges with chatter, stemming from simultaneous developments in engine power, chassis stiffness, and Michelin tire construction. Despite a mid-season wrist injury for Rossi, the M1’s issues were largely resolved in the latter part of the year, and Rossi nearly closed a significant points gap to Nicky Hayden, ultimately finishing just five points behind in the championship standings. Rossi won 5 races that season, compared to Hayden’s 2.
Regulation changes in 2007 reduced engine capacity to 800 cc, and the YZR-M1 transitioned accordingly. The switch to 800 cc eliminated the chatter experienced in 2006. The factory team’s sponsorship changed from Camel to Fiat, and the team initially hinted at running various colour schemes throughout the season. Casey Stoner won the 2007 Championship with Ducati.
Rossi secured the 2008 Championship with a record margin, while teammate Jorge Lorenzo achieved his first M1 victory at the Portuguese Grand Prix, adding to a total of ten wins for Yamaha that year.
In 2012, engine capacity was increased to 1,000 cc, and Jorge Lorenzo won the Championship, closely followed by Dani Pedrosa.
In 2025, Yamaha unveiled a MotoGP prototype YZR-M1 powered by a V4 engine, marking a significant change after two decades of inline-four configurations. Test rider Augusto Fernández debuted the V4 engine at the San Marino GP, focusing on data collection for future development. The new prototype incorporated revised aerodynamics, including changes to the tail, side wings, and bellypan, along with a redesigned exhaust system featuring two mufflers. The introduction of the V4 engine was timed to precede 2027 regulation changes that would reduce engine capacity to 850 cc, potentially limiting the V4’s lifespan to a single season at 1,000 cc.