Rossi: Yamaha bike now much better than late-2016 prototype

In post-season testing in Valencia last year, Rossi was rather underwhelmed by the new-spec Yamaha engine in particular, saying: "The engine is the first evolution of the engine, but sincerely speaking I expected a little bit more, we are not fantastic, I think we have to work still."

However, significant progress was made in time for private testing at Sepang that same month - and as pre-season testing kicked off at the same venue this Monday, Rossi appeared much happier with the bike.

"Fortunately it's better. Today is very interesting because today for the first time we tried the real bikes, my bikes, that I will use for all of the season," Rossi said.

"In Japan they worked hard and made a better bike compared to the prototype that we had in November - engine, we worked a lot on the electronics.

"About the chassis it's the same, but tomorrow we will have another chassis, slightly different, after our comment with the first prototype.

"But the bike is very beautiful."

Asked about the engine in particular, Rossi said: "Today, first touch, good feeling. We have good speed and good acceleration."

Rossi, who finished the day in eighth after having struggled with an "unbelievable headache" in the morning, said such tangible bike improvements compared to the late-2016 prototype came as a surprise.

"We never know a lot from Yamaha, but yesterday when we saw the bike, [we could see] they did a good job," he added.

"The bike is very good under all of the small particulars and is a lot better than the first prototype. It was a good surprise. But, yes, we have a lot to work."

Additional reporting by Scherazade Mulia Saraswati