The 26-year Australia led the pack in Thursday’s first practice session at Losail, and also the fastest on the first of two runs on Friday. The Honda rider was followed by 2010 world champion Jorge Lorenzo of Yamaha Italia in both events.
American Nicky Hayden Ducati, who else has won the championship, finishing third on Thursday – while Honda’s Andrea Dovizioso was in that position after the opening Friday.
Stoner has performed brilliantly during the pre-season testing along with the Spanish team mate Dani Pedrosa, who was fourth last year after an injury-hit season.
“We started this evening with huge chatter issues and I was a little afraid we couldn’t fix this but after a few more exits we managed to reduce it to a more comfortable level,” Stoner, who has won the world title with two different teams, said on the MotoGP website after Thursday’s session.
“This is a positive point for the weekend but with such a short session it’s slightly strange. It was an okay start.”
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In contrast, it was a slow start for Valentino Rossi, a seven-time world champion in the sport’s premier class, who finished the Thursday session in 10th place and the same again in Friday’s first run.
The Italian rider will be hoping to make a comeback after a disappointing 2011 season, his first with Ducati after a long period of dominance at Yamaha.
Valentino Rossi and teammate Hayden must also familiarize themselves with the still-new Desmosedici GP12 machines.
“I used the hard tire the whole session, trying to do a lot of laps in order to understand it. The new tire is much better for warming up, so good for safety, but it started to slide a lot after some laps and made some of the under-steer worse,” Rossi said.
“We have to work with the setting and also the electronics. The soft will be important for Saturday (qualifying), but the hard will be the tire for the race.”