Yamaha 'discovered' 2017 bike in Sepang test

Rossi tried the 2017 M1 during the post-season running at Valencia, but he crashed on the opening day and was not sold the new engine.

His new team-mate Maverick Vinales did not try the upgrades at Valencia, but both riders spent time on it one week later at Sepang, which boosted Rossi's enthusiasm.

"I had the first touch in Valencia, after the race, but after we moved to Sepang we could have more kilometres, more work on the new bike," he said.

"We discovered a very good potential. It looks like we can be stronger.

"Now it's important to work in the three tests before the first race, where Yamaha will also bring new stuff, and try to arrive ready in Qatar for the 26th of March.

"The first impression is very positive.

"Everybody was very curious to see the bike, but in the end it's the normal development.

"If you look at the bike from the outside it's exactly the same.

"Valencia is a difficult track to understand the potential of the bike, but in Malaysia we worked more and it's true that it's not a big change, but the potential is high."

While the new Yamaha is not the revolution mooted late last year, Yamaha chief Kouichi Tsuji says "inside the bike, it's completely different from last year's" model raced by Rossi and Jorge Lorenzo.

He agreed with Rossi's view that the running at Sepang - where 2017 pre-season testing starts on January 30 - was important.

"The bike, the character of the Yamaha, is handling," he said.

"A Yamaha bike used to have good braking, corner speed, very good agility.

"This year's developing concept [goes] back to our concept, back to our philosophy to get again the Yamaha bike character.

"We saw last year at Valencia and the private Sepang test, we had a very positive feeling from both riders about the development direction.

"We have to wait another three tests, but the first step is to get back to the Yamaha YZR bike character."