Valentino Rossi felt he had little to show for his 65 laps of the Chang International Circuit, on Saturday at the Thailand test.

Riding the day after his 39th birthday, where he had highlighted the M1's electronic weakness in terms of acceleration, the Italian reported 'we didn't find a good solution' after finishing 14th on the timesheets, 0.919s from Honda's Marc Marquez.

"It was a difficult day, because we started this morning in quite a good way, I did some good rhythm and I was faster compared to yesterday and was not so bad," he said.

"But after, we have a long list of things to do, we have a lot of work. We worked a lot with the setting to try to improve, we worked a lot with the electronics to try to improve the acceleration, but sincerely, we didn't find a good solution.

"Unfortunately during the day, we are not able to improve.

"At the end, in the afternoon, we also tried some different tyres for Michelin, because it looks like they modified the casing for the October race, but sincerely, I didn't feel very good, so we need to do something else tomorrow."

Asked what sort of race he expects to find in October, a break away or a big group, the Italian replied:

"Very difficult to say. Quite impossible. What we can say is that it is a track with not a big difference in the lap time, so maybe a group race. But you never know."

Are there many places to overtake?

"You have some hard braking that you can overtake, especially Turn 3. In the other part, I think it's more difficult because it's quite tight."

Team-mate Maverick Vinales and Tech 3's both made late improvements to fourth and fifth.

"Honestly it took such a long time to understand the way to go on the bike, maybe too much," Vinales said. "Until the afternoon I didn't start to feel good on the bike, feeling that I can ride in a good pace. But anyway at the last moment we changed some things, it seemed to improve, maybe it is the way to follow tomorrow."

Pressed on the changes he added:

"Especially following my own feelings and my own set-up. That's when I feel good, when I have my bike and when I can ride as my riding style. So tomorrow we are going to check. Now we have to improve the rhythym. I think we did an incredible step in the afternoon, already on '30 on the rhythym and that's the most important."

The Thailand test concludes on Sunday evening.