Repsol Honda’s Casey Stoner and Dani Pedrosa topped the timesheet at the halfway point of day one in Malaysia, as stormy weather conditions plagued the second half of the day at the Sepang International Circuit on Tuesday.

The first day of the second pre-season meeting at the Malaysian circuit wrapped up with Casey Stoner on top of the timesheets.

The Repsol Honda rider’s fastest lap set in the morning session of 2’01.761 remained the fastest of the day, as heavy rain at the mid way washed out much of the afternoon’s testing.

Riders commented that high track temperatures (40C) and slippery track conditions in the morning reduced the pace from the first Test in Sepang a month ago.

Stoner ended his day after just 16 laps, while team-mate Pedrosa ventured out after the weather cleared to continue working to find a better position on the RC213V.

The Spaniard was happy to finish the day having found improvements that allow him to better handle the heavier 1000cc bike under braking.

Yamaha Factory riders Jorge Lorenzo and Ben Spies completed the day third and fourth fastest, with Lorenzo testing a new engine though the slippery track in the morning and rain in the afternoon prohibited testing its full potential.

Alvaro Bautista completed 24 laps to end the day with his best time of 2’02.959 placing him in fifth position. The San Carlo Honda Gresini rider is taking advantage of the test to work on riding position and geometry as he continues to adapt his riding style to the 1000cc machines.

Returning from surgery just three weeks ago, Nicky Hayden closed out the day in 6th place with a time of 2’03.132. The Kentuckian said via a Tweet that although he is not yet 100 percent recovered, he feels much better than he expected.

He also reported to motogp.com that he planned to work on improving traction through small bike modifications though it has been difficult to test thus far because of the challenging track conditions.

With water still on the track, Ducati team-mate Valentino Rossi was the first to return to the asphalt, donning wet tyres and continuing to work on GP12 electronic package, traction, and corner exit acceleration. His best lap from the morning of 2’03.245 placed the Italian eighth for the day.

Monster Yamaha Tech 3’s Cal Crutchlow and Andrea Dovizioso concluded the day in seventh and 11th positions, respectively. The Italian rider struggled with a rear brake issue as he continues to adjust his riding position to fit the Yamaha.

Héctor Barberá (Pramac Racing) and Stefan Bradl (LCR Honda) finished ninth and tenth, with newcomer Bradl feeling confident with his progress on the premier class bike as he continues to work on the Honda’s electronics.

Colin Edwards (NGM Mobile Forward Racing) tested a new seat and a new chassis for the Suter-BMW, completing the day 12th ahead of Ducati test rider Franco Battaini and the Avinitia racing riders Ivan Silva and Yonny Hernandez.

Karel Abraham (Cardion AB Motoracing) withdrew from the test after right shoulder and back injuries he suffered in a big high-side crash at Jerez last week proved too painful to continue.

2012 MotoGP February Sepang Test (day one):
1. Casey Stoner 2:01.8
2. Dani Pedrosa 2:02.0
3. Jorge Lorenzo 2:02.4
4. Ben Spies 2:02.8
5. Alvaro Bautista 2:03.0
6. Nicky Hayden 2:03.1
7. Cal Crutchlow 2:03.2
8. Valentino Rossi 2:03.2
9. Hector Barbera 2:03.6
10. Stefan Bradl 2:03.8
11. Andrea Dovizioso 2:03.8
12. Colin Edwards 2:05.5
13. Franco Battaini 2:05.6
14. Ivan Silva 2:08.1
15. Yonny Hernández 2:08.8