Yamaha’s switch to a V4-powered M1 was tested under a difficult spotlight at the Sepang pre-season test, where engine failures, handling peculiarities and a rider injury disrupted the program. The factory team sat out the second day on safety grounds after unspecified engine problems affected Fabio Quartararo and Toprak Razgatlioglu; Quartararo crashed on the first day, fractured a finger that required surgery and was ruled out of the remaining days. Reports from the test said both Quartararo and Razgatlioglu destroyed engines during the outing, while Alex Rins added that an unnamed rookie also broke an engine during the program. Yamaha paused running to investigate overnight in Japan and Italy, then resumed later with reduced mileage, using D-concession status to preserve options for further engine work and private tests.

On pace the new V4 left Yamaha more than a second off the outright lap times and last among the five manufacturers, with sporting manager Maio Meregalli singling out power as the primary shortfall even as he described the chassis and balance as satisfactory. Jack Miller, who began the official test 14th and finished the final day 17th, downplayed the fault while also saying he needed more consistent track time; he recorded an average top speed of 327.8 km/h — roughly 10 km/h down on Fabio di Giannantonio’s Ducati — and was the only Yamaha to complete a ten-lap race simulation, which left him 13.957 seconds shy of Alex Marquez’s best Sprint benchmark that afternoon. Alex Rins was the quickest Yamaha on pace in 12th, but limited running across the squad made it difficult to assess the package conclusively.

Beyond outright power, riders reported handling disturbances: Razgatlioglu experienced a recurring Michelin rear-tyre behavior when lifting the bike to about 25 degrees that only calmed when the gearbox was shifted into fifth or sixth. Jack Miller declined to elaborate on the technical causes when questioned, and other riders gave similarly guarded responses, underscoring unresolved reliability and safety questions heading into the rest of the pre-season. Yamaha now shifts focus to the final pre-season test at Buriram on February 21–22, where early development work will concentrate on extracting more engine performance and resolving the issues uncovered at Sepang.

Sources