Yamaha's star MotoGP rider Fabio Quartararo has issued a rather muted first verdict on its new V4 bike, saying it has not yet meaningfully addressed the weaknesses of Yamaha's primary bike.
The V4 prototype made its competitive debut in the hands of test rider Augusto Fernandez during the San Marino Grand Prix.
It occasionally ran comparably to the inline-four Yamaha M1s - or at least the ones not being ridden by Quartararo - during the weekend, but struggled in race trim, finishing over a minute back from winner Marc Marquez's Ducati on Sunday.
Quartararo had sampled the bike in private testing at Barcelona on the Monday before the Misano weekend, along with Alex Rins and Jack Miller, but all three were asked not to discuss the bike publicly during the San Marino GP weekend.
But after riding it again during the post-race test at Misano, Quartararo was free to talk about the V4 - and admitted he wasn't enamoured, saying of his feeling on the bike that "at the moment it's worse".
The wait is finally over ⌛️ Fabio just took the prototype for a spin 🏍️💨#PlanV | #MonsterYamaha | #YamahaMotoGP | #YamahaFactoryRacing | #MotoGP | #SanMarinoTest pic.twitter.com/xiTtEUmvSR
— Monster Energy Yamaha MotoGP (@YamahaMotoGP) September 15, 2025
"The sensation is really similar [to the inline-four bike]," he said.
"We saw some things that of course we have a lot of work [to do]. Feeling is still of course not there. Nothing to add."
Quartararo logged 36 laps before the midday break of the test, and was a second off the leading pace.
"In Barcelona we felt some difference that was for me in a better way. Here we haven't found it yet," said Quartararo - explaining that Barcelona didn't offer the same 'many corners in quick succession' challenge that Misano does, and which seemed to expose that the bike is "super aggressive".
"At the moment I don't see any improvement in the area that we really need to make. But like the team said, there is still margin, theoretically."
Quartararo said he had "zero problems" adapting himself to a V4 engine after riding an inline-four for all of his MotoGP career.
Fernandez's assessment after the weekend was that the V4 bike was already competitive at its peak but capricious - struggling for consistency of performance, and not yet offering the right balance between front and rear.
The test rider felt it had, as anticipated, given away some of the other Yamaha's front-end strength in favour of a better rear end of the bike.
But Quartararo didn't sound convinced.
"Of course the [front] feeling of the inline-four is really good, it's the strongest point of the bike, but it's the only one that we have. This one is maybe a bit worse [at that], right now, but we didn't find any other really-positives. So this is what we are going to try and try to figure out what is possible."
He said the feedback is the same among riders but "it doesn't mean it's good". And he added he "will not answer" as to what he sees the potential of the bike being.
Miller much more impressed
A considerably more positive assessment came from Miller, who was eight tenths back from Quartararo but described the bike as "doing all the right things" and just needing time and set-up work.
Miller said it "got better" every time he exited the garage, and also quipped: "You can’t reinvent the wheel in a day, you need at least a week for that."
Asked about the contrast between his assessment and Quartararo's, he said: "I'm not going to be negative about it.
"They're doing their best, and I understand his frustration, I understand where he's at - his need for a competitive machine. These things take time. We need to develop it. It's a new platform, a brand new project.
"Unfortunately in MotoGP we don't have as much time. I understand, for sure, on his side the need and the want- because we see he's got the talent, there's no question marks about that. But, yeah, I think my comments are clear to Yamaha, in terms of what we need to make it more competitive."
