Yamaha’s new V4 engine suffered unexpected failures at the Sepang pre-season test, forcing a safety-first shutdown of factory running and disrupting the team’s program. An unforeseen fault first appeared on one of Fabio Quartararo’s bikes after his opening-day crash and was followed by a separate engine breakage on Toprak Razgatlioglu’s machine; Yamaha described the problem as something “we never had,” halted Wednesday running while engineers investigated, and kept garage doors closed as a precaution.

Engineers initially could not find the cause but later identified the issue and allowed limited on-track activity under strict limits, running the V4s with reduced power and rev limits to protect riders and equipment. The team removed long 60-70 lap runs and focused on ergonomics and sprint work. Yamaha intends to bring replacement engines ahead of the next two-day pre-season test at Buriram on Feb. 21-22 to verify fixes and assess whether the imposed limits can be lifted, and warned that ambient temperatures above 30°C may exacerbate the faults.

The engine problems, combined with Quartararo’s crash — he suffered a broken finger, tried to continue but was later diagnosed and flew home, missing MotoGP’s Kuala Lumpur season launch — intensified scrutiny around the test. Spanish reports that Quartararo had decided not to renew and had reached an agreement with Honda remain unconfirmed; Quartararo has publicly denied signing for Honda while acknowledging he is in discussions. Team director Massimo Meregalli said the Sepang interruption was an unexpected delay that pushed some evaluations and contract talks toward the next test rather than changing decisions about Quartararo’s future, and Alex Rins, the only factory Yamaha rider present, said the issue appeared under control and still managed his quickest laps of the test.

Sources