Yamaha's Jorge Lorenzo has shaken off any rust from missing the final three races of 2011 due to injury by posting the fastest time on the first day of pre-season MotoGP testing.

Morning rain limited track time on Tuesday as Yamaha dominated the first of the three days of tests at Sepang, with three of its riders among the top four, as teams unveiled their new 1000cc bikes.

MotoGP has moved to litre-class machines this year in place of the earlier 800cc engines.

Lorenzo's 2011 season ended prematurely when he crashed during warm-ups for the Australian Grand Prix, but he set the fastest pace on Tuesday, in hot and humid conditions with a 2min01.657 lap with Honda's Dani Pedrosa next on 2min02.003.

ROSSI FIFTH

Yamaha's Carl Crutchlow posted a third-best 2min02.221 while his team mate Ben Spies followed on 2min02.234.

Multiple World champion Valentino Rossi, who struggled through a difficult 2011 season, posted the fifth fastest lap time of 2min02.392 on the revised Desmosedici GP12.

Pedrosa shrugged off the strong Yamaha performance, saying he was still getting the feel for his new Honda.

He said: “I am focused on myself. I was most of the time alone on the track and was not mixing with the other MotoGP riders.

“I hope to do better tomorrow. Tomorrow we will start to find the proper setting of the bike.”

STONER SIDELINED

Reigning champion Casey Stoner, meanwhile, failed to show whether he could maintain his form on the new bikes after pulling a back muscle doing warm-up exercises just before morning testing, keeping him off the track.

Stoner, who will be chasing his third premier-class title this year, received treatment and was hopeful of riding on Wednesday.

He said: “I was stretching this morning for a good 20 minutes preparing to go out on track for the first time and then all of a sudden my back just locked up on me.

“I couldn't move or do anything. I had to call somebody to come and help me move into a position that was less painful.

“I had some more physio after lunch but it still wasn't easing up, I felt I could have gone out on the bike in the afternoon but we all agreed it would probably make it worse for tomorrow,” said the 26-year-old.

The test will end on Thursday and Stoner is keen to get out and try parts for the new 1000cc Honda.

He said: “I think tomorrow the track conditions will be better and as long as my back improves overnight we should get back on schedule with our testing,” he said.

EMOTIONAL RETURN

The testing session marked an emotional return for riders to the Sepang circuit for the first time since Honda rider Marco Simoncelli died here in a crash on lap two of October's Malaysian MotoGP.

On Monday, Honda team officials laid a flower wreath at Turn 11, where the 24-year-old Simoncelli was killed, and observed a moment of silence.

Simoncelli's death highlighted concerns about Sepang, which is notoriously tricky due to heat, humidity and frequent rain, but Dorna managing director Javier Alonso said Simoncelli's death was purely an accident that should not be blamed on the circuit, which was dry at the time of the crash.

He said: “In terms of safety, Sepang is a very safe track. Unfortunately we had a fatal accident last year. We are really, really sad about this.

But he added: “Safety-wise, Sepang is one of the safest tracks we have in the championship.” - Reuters

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