The mystery that is Yamaha’s improved top speed returns at Sepang, what next?

So often during the 2022 MotoGP season Fabio Quartararo was let down by a lack of top speed compared to eventual world champion Francesco Bagnaia and Ducati.

So it’s no wonder that the Frenchman, who had a bike as capable as the Ducati in many other areas, was pleading with the Iwata-based manufacturer for upgrades that would make his job easier.

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Unfortunately that was never to be the case as Quartararo’s only chance at testing a brand new engine was in the form of post-race tests in Misano and Valencia.

But that’s where things get interesting, or perhaps confusing based on which way you look at it, as a new engine was debuted in Misano with very positive results.

Quartararo set a top speed of 298.3km/h, albeit in the slipstream of Franco Morbidelli as he finished just shy of Jorge Martin’s 300.0km/h.

Still, signs were there that Yamaha had made the required gains to become a force against Ducati and others in what was clearly their most pressing area of concern.

In fact, speaking after the test, a very pleased Quartararo said: "This morning we worked pretty well on the electronics of the new bike because the character of the engine is slightly different. The top speed looks really good, so I feel super happy! It‘s a great feeling.

"I got a great slipstream to set the 298km/h top speed this morning. But the average of the speed was also good, compared to the others, this is super important.

"We still need to work on the first part of acceleration and improve more. But we are only in September. We still have the Valencia test, then Sepang and Portimao."

Then came a very quick and surprising drop in top speed during the final test of the year in Valencia.

After losing his MotoGP title to Bagnaia, Quartararo made his second appearance with the 2023 engine, this time with the effects being much less impressive.

Quartararo added: "I'm surprised because actually this engine was supposed to be a little bit faster than the one we tested in Misano and Barcelona [but] I found it was the same as [the 2022 engine] two days ago.”

"Especially on the qualifying lap. We compared the speed and it was the same. So we have to analyse what happened because we had two tests - Misano Barcelona - then Cal [Crutchlow] did Motegi and Jerez and they saw a difference on the [new] engine.

"But right now, there was no difference. So we have to analyse really well what happened."

"It's not the way I wanted to end the year, but at the end something went wrong. It's not possible that in Misano and Barcelona we felt an improvement and today there is nothing."

"Normally this engine has more horsepower and in Jerez [a week ago] Cal tried it and it was clearly better. But right now [here] the top speed with last year is the same. There is a problem for sure! I mean not in the engine, but something happened that we didn't have this extra power that we were expecting.

"It was not a wasted [day] but, a weird feeling I would say. At Misano when I went through the gears I felt that the engine had something. Today, no!"

Fast forward to the present time and Yamaha’s unpredictable top speed made a resurgence during the recent Sepang Shakedown test as Cal Crutchlow was rumoured to have clocked a best of 335.4km/h, which is one km/h slower than the record at Sepang set by Enea Bastianini. 

Crutchlow also recorded a speed of 330.0km/h on the opening day when conditions were less than favourable, meaning Quartararo and team-mate Morbidelli should have something to build upon during the official three-day test.