Monster Energy factory Yamaha rider Valentino Rossi revealed his has ditched some of the new Yamaha upgrades in Japan, in a bid to solve the rear tyre issues that have plagued the Italian in recent rounds.

The Iwata factory have been working hard to bridge the gap to Honda, Ducati and even Suzuki, and in recent races has seen the Yamaha challenging at the front, even if they haven’t had the wins to show it. Yamaha supplied Rossi and his factory teammate Maverick Vinales with a multitude of new parts after the British Grand Prix at Silverstone when they had a test in Misano. Among the new pieces tested was a new twin exhaust and carbon swingarm.

Issues with rear tyre grip in the following races means that ahead of the weekend in Japan, the Italian decided to revert back to his old exhaust and swingarm, using the limited track time to focus on setting his bike up rather than testing new pieces.

“In the last two races I’ve had a lot of problem with the rear grip and I’ve suffered more than the other Yamahas,” said the 40-year-old.

“For me, and the exhaust, we are not ready, because it looks like that it is not at the same level of the standard. We need more time. But, unfortunately during the race weekend you cannot do anything. You always try performance. We will see this winter.

“About the carbon swingarm, for me, it’s not a difference. It’s not worse, but we decided to go to the other.”

With the older pieces, Rossi ended the opening day in Motegi in fifth place, a fraction over seven tenths of a second behind Yamaha stablemate Fabio Quartararo. A brake issue on his first bike left the Italian with a lot of time on his second bike as he attempted to work on race set up.

With heavy rain forecast for qualifying, Rossi was eager to find himself in the top ten and not have to go through Q1 and managed to do that just in the nick of time.

“We tried to save a bit of time to do the time attack at the end, because the forecast for tomorrow is very bad,” he said.

“Unfortunately, we had a problem with the brakes on the first bike, so we had to take out the tyres and put them on the second bike, which was set up a bit different, but at the end I was able to start my second lap of run four with just ten seconds to spare. I did a good lap and I’m in the top ten, that’s very important because it looks like tomorrow the weather will be bad.

“For the rest, it’s not so bad. My pace is quite good. As always, we need to understand the tyres, because a lot of riders also use the soft rear, which looks like it’s a bit faster. We’ll see.

“We have to keep working, but my pace is quite good, and the first day was quite positive.”