Valentino Rossi says he needs to find more grip from his Yamaha on Saturday if he is to stand any chance of challenging Casey Stoner's Ducati in the Qatar Grand Prix.
Stoner – who has won the last three Losail MotoGP races – dominated practice on Friday, with Rossi half a second adrift in third. The MotoGP champion admitted his times had been disappointing in the opening session and that Yamaha needed to find a solution.
"We expected a bit better performance," said Rossi. "The lap time is not so bad. But I think it's possible to try to go faster, and if we want to try to fight with Stoner, we have to improve.
"I have too much sliding and not enough grip. If I try to go faster, I slide more. So we need to make some modifications."
Rossi felt Stoner had raised his game this weekend, but that he could pinpoint where the Yamaha was currently losing out.
"He's faster than in the test, he's able to go 0.2sec, 0.3sec faster," said Rossi of Stoner. "In general we lose it all in 600 meters – because through Turns 7, 8, 9 and 10, I lose 0.3sec. In the rest of the track we are close, more or less. So we have to understand why.
"Always when I touch the throttle, I spin [the wheels] too much. I don't have enough grip. Unfortunately, it's not just traction – I don't just lose drive – I also lose the [racing] line because the bike slides to the side. We have some ideas for tomorrow. Our work is to try to catch Casey."
Stoner declared himself quietly content with his Friday performance - and warned there was more speed to come and little chance of him getting complacent.
"Today felt really good – we had a similar rhythm to the test and I didn't feel to be pushing too hard," said Stoner.
"This is obviously a good circuit for me but we're taking things steadily. The target for this weekend is to take away some solid points and make a good start to the season.
"It is early days and we're not getting carried away. We set some good lap times today but everybody else will improve so we have to work hard tomorrow and make sure we stay on the pace right through until Sunday night."