Repsol Honda's Casey Stoner has picked up where he left off at the Malaysian circuit of Sepang, setting the quickest time on day one of MotoGP testing but the Aussie is some way off his best of 1'59.607 from the first outing earlier in the year.

Stoner set his time early in the day and only completed 16 laps as the track is dirty and in not ideal condition as there was a car test session held not long ago. Some riders complained that is it very slick and this would go some way to explaining why laptimes are two seconds down.

Rain also stopped play in the middle of the day (I'm a poet, etc) but Stoner clocked up a 2'01.761 to go two tenths faster than team-mate Dani Pedrosa and a whopping seven-tenths quicker than 2010 World Champion Jorge Lorenzo, who spent the day testing modifications to the Factory Yamaha's gearbox to improve stability.

"It was really hard to leave Switzerland, Ally woke up for a feed at the same time as I was leaving for the airport and I didn't really want to leave! The first day of testing has gone well, we started off where we left last time but the track conditions have been a little worse," said the Australian.

"We have a some work to do, this morning we managed to compare a few things back to back, we've tried a new set of brake disks to try and reduce the brake fade that I've been having at the last test so that's been an improvement. We're trying a few other things with set up, to shorten the wheelbase and get a little more traction.

"We have a couple of things we can try to change the stiffness and also move the weight around a little bit to try and upset the chatter and reduce the frequency. This afternoon I have no doubt we would have gone a second or a second and a half faster, but the rain came out and the track didn't dry up enough to warrant going out so we'll wait until tomorrow."

American Ben Spies, on the second works YZR-M1, is another four-tenths behind his team-leader while Alvaro Bautista shimmied into fifth place on the San Carlo Honda - the first satellite bike on the timesheet with a 2'02.959 and is only a tenth slower than the former World Superbike Champion.

Nicky Hayden was the first of the factory Ducatis but he and team-mate Valentino Rossi were keen to get in as much track time as possible, exiting pitlane when the surface was still wet. The American set a 2'03.152 while The Doctor was two places further back in eighth on a 2'03.245.

In between them was Cal Crutchlow's Monster Yamaha, lapping in 2'03.213. He is working on a base setup and some corner entry settings while Hector Barbera and Stefan Bradl round out the top ten. Andrea Dovizioso just stayed ahead of Ducati tester Franco Battaini, who is riding the AB Cardion bike because Karel Abraham's Jerez crash injuries forced him to call it a day very early on.

Forward NGM's Colin Edwards is the first of three CRT bikes in the mix. The Texan lapped faster than Battaini on a 2'05.510 and easily outpaced the rest of the non-prototypes. Ivan Silva and Yonny Hernandez, both on Avintia bikes, were in the 2'08s.

Sepang MotoGP test day one - conditions dry (save for a brief downpour)

1 Casey Stoner Repsol Honda Team 2:01.761 - - 16

2 Dani Pedrosa Repsol Honda Team 2:02.005 +0.244 +0.244 36

3 Jorge Lorenzo Yamaha Factory Racing 2:02.436 +0.431 +0.675 22

4 Ben Spies Yamaha Factory Racing 2:02.819 +0.383 +1.058 31

5 Alvaro Bautista San Carlo Honda Gresini 2:02.959 +0.140 +1.198 24

6 Nicky Hayden Ducati Team 2:03.132 +0.173 +1.371 55

7 Cal Crutchlow Monster Yamaha Tech 3 2:03.213 +0.081 +1.452 27

8 Valentino Rossi Ducati Team 2:03.245 +0.032 +1.484 39

9 Hector Barbera Pramac Racing Team 2:03.612 +0.367 +1.851 24

10 Stefan Bradl LCR Honda 2:03.820 +0.208 +2.059 31

11 Andrea Dovizioso Monster Yamaha Tech 3 2:03.830 +0.010 +2.069 23

12 Colin Edwards NGM Mobile Forward Racing 2:05.510 +1.680 +3.749 25

13 Franco Battaini Cardion AB Motoracing 2:05.563 +0.053 +3.802 11

14 Ivan Silva Avintia Racing 2:08.109 +2.546 +6.348 32

15 Yonny Hernandez Avintia Racing 2:08.767 +0.658 +7.006 16