Yamaha's updated engine specification got its first public run out at the Valencia MotoGP test and while Valentino Rossi said it is a positive improvement, he added has hasn't gone far enough.

Rossi reported the upgraded motor is better on engine braking and corner entry, but it is still spinning and wearing the rear tyre too much. Both he and Maverick Vinales have another spec to try in the morning.

“It’s not enough. Today we try one. Tomorrow we have another one which is a bit similar but different. The plan tomorrow, the most important thing is to try the different spec," said Rossi, speaking at the track.

“We have one evolution engine that we already tried during the season. And we compared with the standard engine. It’s not so bad because it helps to stress less the tyre and at the end it’s a good work.

“We always suffer about tyre degradation so we try to make an engine that is more smooth, more soft to try to stress less the tyre. It was not so bad because my lap time was quite good. I have a good feeling for the first day.

“We try to have a more soft character to spin less and it’s already a help. But for me it’s not enough. We suffer too much with the rear tyre degradation. It’s also true that today the conditions were very bad and the tyre normally suffer in these conditions.

“It looks like already after some laps we slide too much. So we need to continue to work, but it looks like we take a good direction.

“The engine change also in the engine brake, in the entry. It’s a small help because become more easy to ride and you can be more constant. Also in acceleration it’s more or less the same.

“For me these two tests are not crucial. But they’re important. We have time to choose the engine before next February. But at this test we can give a good indication to work more in one way. So this is our first target here and at Jerez.”