New MotoGP world champion Fabio Quartararo has frequently emphasised the need for Yamaha to address its top speed deficit to the Ducatis for 2022.

Unfortunately for the young Frenchman, if such major engine updates are in the Yamaha pipeline, they won't be arriving until next year's Sepang test.

Quartararo described the 2022 prototype seen during Thursday's opening day at the Jerez Test as basically the same prototype bike he tried at Misano in September.

"Well, we tried a really similar bike to Misano [test]. Well, to be honest it was the bike as Misano," began Quartararo, who set the ninth fastest time (+0.707s). "So we tried that and then we tried more things that is a new swingarm, some electronics. But to be honest it was a really similar test as Misano.

"I didn't try a new chassis today, just my '21 bike and the new ['22] bike, that actually is the bike of the Misano test, but in Misano we had in grey and now it's in black. It's the same just the paint.

"For me [with the new chassis] we are looking for a little bit - not corner speed - but a little bit more turning in the slow corners.

"More work needs to be done to feel an improvement [in speed] but as you can imagine the bike is the first step and we hope for much better in Sepang.

"We still have a day of tests tomorrow and we'll try some new items, I expected a little bit more, but I hope they [Yamaha] kept the best for Sepang and have more speed. That's the thing that we need; more speed."

Quartararo took five wins during the opening 12 rounds of this season, after which Francesco Bagnaia and Ducati took four victories with the remaining two for Marc Marquez and Honda.

The 22-year-old spent the closing races struggling to overtake after his scorching qualifying form faded and said the size of the top speed deficit was clear even at a tight, compressed circuit like Jerez.

"[Jerez] is a good track to test the chassis, to try the engine is more difficult because the straights are really small and you can't really see. But what I'm seeing is that with the Ducati on this small straight we have 8km/h [less top speed]. This means we still have a lot of work."

Quartararo insisted there is still time for Yamaha to address its engine performance, adding that the rest of the bike is already strong.

"I'd say we have three months to find that power that at the end to be honest, the 2021 bike, I would not say it's perfect because it’s never perfect, but our base was really good," he said.

"We are missing just a lot, a lot of top speed and aerodynamics. So that's why I'm pushing so much every day to have this in Sepang, because here we don’t really see, let's say… because it’s more-or-less the same as the Misano test. "

Team-mate Franco Morbidelli was the top Yamaha rider, in seventh (+0.571s), on day one.

The final day of official 2021 MotoGP action takes place at Jerez on Friday. The next test will then be at Sepang in early February.