Rossi: Yamaha have closed power gap

Ducati enjoyed a notable straightline speed advantage in the opening races, and Casey Stoner led a team one-two in today's session.

But despite only being fourth fastest this afternoon, Rossi believes Yamaha have taken a step forward.

"The Japanese engineers have been working very hard during the break and today we tried out some new modifications for our engine," he said.

"My first impressions are that it's a definite improvement and we can go a little bit faster. It's not a big difference but it's very important, especially here at this track. Now let's see what we can do tomorrow."

He was also pleased to be competitive at Istanbul Park, where he had only qualified 11th in 2006.

"However we're not in such a bad position in fourth and when you compare it to last year, when we had some serious problems here, things are much better and I can ride the bike very well," said Rossi.

"In fact I like the track a lot more with this bike."

Rossi's teammate Colin Edwards was fastest in the morning session, but slipped to 13th in the afternoon.

"Strangely I felt more comfortable with the front end this morning, when the track was wet and even dirtier than it was this afternoon," he said.

"Unfortunately we've got some problems to deal with in the front-end and we didn't quite get to the bottom of them today."