Valentino Rossi heads for this weekend's British MotoGP having spent a day of private testing at Misano on Sunday.

Yamaha's ongoing acceleration weakness led to a shock post-qualifying apology from M1 project leader Kouji Tsuya last time in Austria, where Rossi went on to ride from 14th on the grid to sixth.

During his apology, Tsuya said that private tests would be held either side of the British MotoGP to work on a solution, which Rossi describes as part-electronics, part-engine (he is happy with the 2018 chassis).

The first of those tests took place at Misano on Sunday, where Rossi said he tried "different set-ups and electronic solutions" as well as preparing for his home event in September.

"We've got a lot of work done at the Misano test," added team director Massimo Meregalli.

However it's still unclear if any progress was actually made - Rossi and team-mate Maverick Vinales having preferred their standard machines at the end of previous tests. Favourable electronic updates could be used straight away, while any engine design changes would need to wait until 2019.

More should be known at Silverstone, where Vinales and Rossi were narrowly beaten by Ducati's Andrea Dovizioso last year, as both Yamaha riders crossed the line within 0.75 of victory. 

The result kept them in title contention, but Rossi broke his leg in a training accident shortly afterwards while issues with the 2017 M1 chassis saw Vinales take just one further podium by the end of the season.

Yamaha's MotoGP losing streak has now reached 21-races, their longest drought since 1998. Rossi remains second in the world championship, 59 points from Marc Marquez and now only 12 ahead of Austria winner Jorge Lorenzo

"Now we go to Silverstone, a track that I really like," Rossi said. "As usual, with my team we will work strongly to achieve the best results. I hope that at Silverstone we can be fast, so I can have a good race."

Meregalli added that in contrast to the stop-start Red Bull Ring, the fast, flowing nature of the Silverstone circuit "suits our bike well and our riders both like its fast corners and sweeping lines. Last year we secured a double podium, and this year we'll fight even harder. "

Vinales is fifth in the world championship.