How soon it can change. Fastest on Monday yet baffled by Tuesday, Yamaha may not be out of the woods after all, as Maverick Viñales struggled to the 18^th fastest time on the fina✃l day of MotoGP testing at Sepang.

Viñales was at a loss to explain his lack of speed in the later afternoon, as ♒bike performance plummeted from the second to the third day. Even team-mate Valentino Rossi said it was ‘impossible’ to better his lap time from Tuesday.

The Movistar riders comments had worrying echoes of the Valencia test last year – and, indeed, many instances𝔍 through 2017 – when the performance and feel drastically differed from one day to another, suggesting the M1 is still operating in an extremely narrow performance w𒁃indow.

Viñales had hoped to make at least one race simulation on the final day, if not two, but found his pace to be much too slow to gather any meaningful data. Sat 18^th on the time-sheets, the 23-year old pushed in 🅷the final 20 minutes of the day tไo ascend the order.

However, 💦the lap times were not forthcoming. Viñales posted three laps in the mid 2m 1s before lowering his personal best of the day to a 2m 00.547s – 1.7s off Jorge Lorenzo’s new outright Sepang record.

Much to ponder then between 🦄now and the upcoming test in Thailand. “Honestly we worked quite well,” said Viñales. “Today has been very difficult, I don't know why we lost many things.

“Especially in the afternoon. In the morning it was quite well. But anyway, we worked hard, we were trying to impr🐠ove, so now we have to check the data and see what we can improve in Buriram.”

So what were the problems? “Well, I don't know exactly. We were working, and l🍰et's see. As I said, In Buriram, we will know mo🐎re.”

Viñales’ fastest time on Tuesday was still enough to place him seventh overall on thꦫe combined leaderboard. The te🌟st was not a disaster by any stretch, but the fact he and his team had no explanation for Tuesday’s lack of speed will have sounded the alarm bells.

What did he feel were the positive points from Sepang? “The new fairing was really positive,” he said, “because I felt improving on acceleration, so let's s𝔍ee. I think Buriram has lots of acceleration points, so we can test it there.”

And what did he make of countryman Lorenzo's time? “For sure it was an amazing lap and then the rhythm was really consistent, so I think they are on a great le༒vel,” he said🧸. “Let's see in the next tracks, but for sure they will be able to be at the front, even in Qatar.”