Movistar Yamaha’s Valentino Rossi believes Yamaha have ‘a long job’ to fix the chassis problems with their M1 but is hopeful solutions will arrive at the next official Sepang test in late January.

Rossi focused on evaluating the M1’s new motor at Valencia with it inside a 2016-spec chassis while team-mate Maverick Vinales was tasked with the frame work but said the new powerplant will not fix their tyre wear problem - that has to come from the metal that holds it in place.

Yamaha will go to Sepang in just under two weeks with the same chassis options but Rossi is hopeful a new version will arrive for the following outing in Malaysia.

“We have to decide and test well some different engine, so we concentrate on that. It’s an important test - and you can’t make mistakes - it’s better to have the same bikes to understand the engine. It was a long day, but was positive,” said Rossi, speaking at the track.

“Valencia is not fantastic for testing the engine because it is quite small. But you can understand and we will continue to try it also in Sepang in ten days time. We will have the same chassis as here. It was already the plan. Because the last chassis that we used was prepared for the end of this season, but we decided to use it before. The engine doesn’t help. We need something else.

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