Evaluating a new engine was the priority for Valentino Rossi during Wednes🌄day's final day at the Valencia MotoGP test.

As such, the𝓰 Movistar Yamaha rider stuck to the 2016 Yamaha chassis he had switched to on Saturday night of the race weekꦐend.

"Today we have to decide and test well some different engine, so we concentrate on that,"🃏 said Rossi, who was seventh fastest, 0.691s from Honda's Marc Marquez.

"Because it’s an important test - and you can't make m♔istakes - it’s better to have the same bikes to understand the engine. It was a long day, but was positive."

The new engine was aimed at providing, "more power witho༒ut losing the smooth character from the bottom [of the rpm]. 

"Valencia is not fantastic for testing the engine because it is quite small. But you can unde🍸rstand and we will continue to try it also in Sepang in𓆏 ten days time."

The f༒act Rossi chose to evaluate the new engine with the 2016 chassis u🍌nderlined that, like team-mate Maverick Vinales, the Italian favours that frame at the Spanish circuit.

But Rossi ruled out the new engine solving the rear-tyre degradation issues, whi♔ch he feels is the main downside of the 2016 chassis.

"No🧜. The engine doesn't help. We🦂 need something else."

Yamaha's privat🌳e Sepang test will now be used to make a final decision on the direction of the 2018 machine; engine and chassis.

"We will have the same chassis [op꧒tions] at Sepang as here," Rossi said. "It was already the plan, sincerely. Because the last chassis that we used [the 2018 prototype, which debuted at Silverstone] was prepared for the end of this season, bu𒈔t we decided to use it before."

Rossi hopes that the final 2018 Yamaha will then be ready ꦓin🥂 time for the next official test, to be held at the same Malaysian circuit in late January.

"I hope it will be ready, because for me Yamaha have to do a longඣ job with the balance of the bike."

In other words, the chassis.