The Italian, who graduated to the factory team from Gresini this season, missed the first five races of 2023 after suffering a broken shoulder blade in the Portuguese Grand Prix sprint race.
Bastianini returned at Mugello, finishing ninth in the grand prix, with a best result of eighth next time out at Sachsenring.
He failed to score at the British GP, finishing 13th in the sprint race before crashing out of the grand prix after tangling with Marc Marquez.
Asked where he was struggling compared to team-mate Francesco Bagnaia, who leads the championship standings, Bastianini said: “The main problem is I’m always like this, like a chopper, my sensation on the bike is this one.
“For timing, it’s not good and we have tried with the rear suspension, we tried to modify the bike a bit but probably we have to try something bigger like Pecco because he changed a lot since last year’s bike.
“I need time to understand this, it was important to do this lap – I made 16 laps – and now I have more data to give to my team and to explain to my team.
“Now probably we say the direction, but it won’t be simple to bring and I don’t know if I can do it in a short time.”
Source: Autosport