MotoGP title leader Casey Stoner, who finished Friday practice at Misano just 0.076sec behind championship rival Jorge Lorenzo, believes there is plenty of room for improvement from his Repsol Honda.
"We made a pretty good step this morning, everything felt pretty good and the bike was working well," said the Australian, who led the first session. "We tried a few things this afternoon, but had a slight problem with some air in the brake line which cost us some time.
"Then we did race distance on the soft tyre and got some good data from that, we're doing some reasonably competitive times but not good enough yet, we'll go away tonight and work in preparation for tomorrow.
"We still need to get the bike feeling a little more comfortable in the middle of the corner and on the exit, with traction as well as turning. If we can improve these areas then I'm confident we can also improve the lap time quite a lot".
Team-mate Dani Pedrosa, last year's winner from pole, was 0.2sec behind Stoner in third.
"We had a good start in the morning, I felt quite comfortable from the beginning, but in the afternoon we didn't improve as much as I would have liked," said the Spaniard. "When Bautista's engine blew in front of me I thought the track would become dirty, so I did some slow laps to check and I lost some time and rhythm.
"We have to keep working with the suspension to get better traction and stability under hard braking, so we will focus on this tomorrow. I tried both tyre compounds, the hard one only this afternoon, and we still don't know which one will be better for the race".
Home star Andrea Dovizioso needs to make the biggest gains, having been left one-second from Lorenzo.
“We need to continue working on the set up to reduce the pitching in the front and the rear," he explained. "This is a slow track but with many hard braking areas and strong acceleration so we will analyse the data to understand the most critical areas where I am losing time.
"We rode with both soft and hard tyres and I felt good on the bike, so now the first thing to do is to study the data and evaluate the best direction to follow in preparation of the qualifying and race. I'm confident that we can recover the gap from the front riders”.