Yamaha’s V4 problem “under control” after Quartararo, Razgatlioglu “broke engines”

Alex Rins emerged as Yamaha’s fastest rider during the manufacturer’s cautious return to action on the final day of the Sepang MotoGP test.

Yamaha’s new V4 machines sat out day two as investigations continued into technical issues suffered by Fabio Quartararo - and it seems Toprak Razgatlioglu - during day one.

That problem was initially overshadowed by the news that Quartararo had broken a finger in an earlier, unrelated crash, forcing the Frenchman out of the remainder of the test.

But after the garage doors remained closed for the other Yamaha riders on day two, a technical issue was confirmed.

Following overnight checks, Yamaha’s riders were cleared to resume testing on the final day, although with restrictions on mileage and intensity.

“Well luckily, all the big things that we had to test we already tested at the Shakedown and first day of the official test,” Alex Rins explained.

“I don’t want to say that it didn’t change anything, because any time that you go on track, you ride and you cannot lose time, especially now.

“We didn’t do any setting on the bike. So the plan for yesterday and today was to try the minimal items and do laps to try suspensions, forks and this stuff.

“Unfortunately, for the problem that we had yesterday we couldn’t.

“So luckily today we were able to ride. Yamaha said to us that we can ride but with care, with calm. I mean, we cannot do many, many laps.”

When asked whether Yamaha had explained the cause of the issue, Rins replied:

“They said to us that we couldn’t ride because Fabio and Toprak broke some engines, so for [safety] it’s better to check everything.

“It looks like they identified the problem and because of this they allowed us to ride. They are [sure] that the problem is under control.

“For Thailand also more engines will arrive, so we will be able to ride more ‘free’. And that’s it.”

Rins completed 26 laps during the morning session, setting Yamaha’s fastest lap of the entire test with a 1m 57.580s, 1.178s behind overall pace-setter Alex Marquez. Rins then added just ten more laps in the afternoon.

The following table shows how that lap time compares with Rins and other Yamaha riders' best laps at Sepang since the start of 2025.

*Did not ride on Day 3.

For comparison, the fastest lap time at the 2025 Sepang test was a 1m 56.493s by Alex Marquez, who set an almost identical 1m 56.402s to lead the 2026 test.

Yamaha riders did not take part in either of the practice start sessions on the final day to help preserve the remaining engines.

Fortunately for Yamaha, its concession status meant its race riders already had extra Sepang track time at the Shakedown and can hold private tests with its race riders.

The factory is also free to modify the V4’s engine design throughout the season to fix any faults that emerge.

The final official pre-season test will be held at Buriram from February 21-22.