Valentino Rossi (Team Movistar Yamaha) took advantage of the Yamaha’s new seamless shift gearbox on the first day test at Sepang International Circuit by topping the time sheets at the end of day one, closely followed by Dani Pedrosa (Repsol Honda) 0.129 behind and Pol Espragaro (Tech 3 Yamaha) was 0.462s behind Rossi.
It was a difficult day for the teams as the track temperature approaching boiling heat of 60 degrees heat at times, leading to a lack of grip, impossible for any rider to post a time comparable to the previous test here at the Sepang 
circuit. Rossi’s best lap of 2’00.414, was 1.5 seconds slower than Marquez’s fastest lap from Sepang 1. With all the fastest times set in the morning, most riders did not venture out on track during the peak of the daytime heat.
A downpour put an end to any meaningful lap times and effectively brought an early end to the days action with 90 minutes to go. It did however allow some of the braver riders to head out and get some “wet” data for their engineers, before a massive thunderstorm caused the red flag to come out halting the session temporarily, before the circuit was reopened with only 20 minutes left.
Both Repsol Honda riders spent Sepang 1 choosing which bike they wanted to develop during this test, but it was Pedrosa who adapted best to the tricky conditions to finish 2nd, over half a second faster than his teammate Marquez.
Suzuki went back to Japan and spent extensive time in the wind tunnel developing a new fairing and also some engine updates to try and coax more power from the GSX-RR, an effort that was clearly paying off. Surprisingly Team Suzuki’s Aleix Espargaro knuckled in ahead of Jorge and behind his brother Pol in 4th with a time of 2:01.055, his team mate, Maverick Vinales completed the top 10 in ninth
Jorge Lorenzo, even with his new gearbox, posted 7 tenths off the leading pace but Lin Jarvis, the Yamaha team manager was happy with the results.
Current World Champion Marc Marquez, managed a best of 2’01.190 for 6th place.
Cal Crutchlow CWM-LCR Honda RC213V, manage to post the 7th fastest lap of the day. 
Bradley Smith who is still recovering from injury to finish just two hundredths behind Crutchlow on the Monster Yamaha Tech 3 YZF-M1 in 8th.
Ducati‘s much anticipated GP15 is smaller than the GP14.3 that Dovizioso and Iannone rode last month, the engine position was change to try and improve the bikes well known problem with understeer. With Dovizioso and I
annone both riding the new bike back to back with the old bike to allow their teams to collect data, they were not focusing on lap times but still managed to take 10th and 15th respectively, and will be encouraged by the start they have made with there new machine which is the first to have its design completely overseen by team boss Luigi Dall’Igna.
Scott Redding finishing 11th on the Estrella Galicia 0,0 Marc VDS Racing Honda, just over a second slower than Rossi.
Aprilia Racing Team Gresini with Alvaro Bautista finishing in a promising 12th just 1.3 seconds off the leaders, but his team mate Marco Melandri just could not get going and ended the day last in 27th place.
Hector Barbera was the top Open class rider on his Avintia Ducati in 13th, while Jack Miller is still struggling to get used to his CWM LCR Honda and could not get under the 2’03 mark, leaving him in 22nd place.
MotoGP Sepang Test2 2015
Session 1 as of 23/02/2015
| Pos | Rider | Team | Fastest lap | Lead. Gap | Prev. Gap | Laps | Last lap | |
|---|---|---|---|---|---|---|---|---|
| 1 | ROSSI, Valentino | Movistar Yamaha MotoGP | 2:00.414 | 25 / 54 | ||||
| 2 | PEDROSA, Dani | Repsol Honda Team | 2:00.543 | 0.129 | 0.129 | 20 / 52 | ||
| 3 | ESPARGARO, Pol | Monster Yamaha Tech 3 | 2:00.876 | 0.462 | 0.333 | 17 / 45 | ||
| 4 | ESPARGARO, Aleix | Team Suzuki MotoGP | 2:01.055 | 0.641 | 0.179 | 17 / 39 | ||
| 5 | LORENZO, Jorge | Movistar Yamaha MotoGP | 2:01.162 | 0.748 | 0.107 | 37 / 51 | ||
| 6 | MARQUEZ, Marc | Repsol Honda Team | 2:01.190 | 0.776 | 0.028 | 24 / 43 | ||
| 7 | CRUTCHLOW, Cal | CWM LCR Honda | 2:01.222 | 0.808 | 0.032 | 13 / 43 | ||
| 8 | SMITH, Bradley | Monster Yamaha Tech 3 | 2:01.241 | 0.827 | 0.019 | 22 / 51 | ||
| 9 | VIÑALES, Maverick | Team Suzuki MotoGP | 2:01.317 | 0.903 | 0.076 | 22 / 50 | ||
| 10 | DOVIZIOSO, Andrea | Ducati Team | 2:01.355 | 0.941 | 0.038 | 5 / 23 | ||
| 11 | REDDING, Scott | Estrella Galicia 0.0 Marc VDS | 2:01.592 | 1.178 | 0.237 | 31 / 52 | ||
| 12 | BAUTISTA, Alvaro | Aprilia Racing Team Gresini | 2:01.740 | 1.326 | 0.148 | 29 / 51 | ||
| 13 | BARBERA, Hector | Avintia Racing | 2:01.926 | 1.512 | 0.186 | 6 / 39 | ||
| 14 | HAYDEN, Nicky | Drive M7 Aspar | 2:02.062 | 1.648 | 0.136 | 26 / 41 | ||
| 15 | IANNONE, Andrea | Ducati Team | 2:02.142 | 1.728 | 0.080 | 16 / 30 | ||
| 16 | PETRUCCI, Danilo | Pramac Racing | 2:02.225 | 1.811 | 0.083 | 9 / 35 | ||
| 17 | ABRAHAM, Karel | AB Motoracing | 2:02.394 | 1.980 | 0.169 | 26 / 28 | ||
| 18 | BRADL, Stefan | Forward Racing Team | 2:02.410 | 1.996 | 0.016 | 19 / 42 | ||
| 19 | HERNANDEZ, Yonny | Pramac Racing | 2:02.606 | 2.192 | 0.196 | 24 / 29 | ||
| 20 | LAVERTY, Eugene | Drive M7 Aspar | 2:02.730 | 2.316 | 0.124 | 28 / 45 | ||
| 21 | DI MEGLIO, Mike | Avintia Racing | 2:02.941 | 2.527 | 0.211 | 23 / 33 | ||
| 22 | MILLER, Jack | CWM LCR Honda | 2:03.006 | 2.592 | 0.065 | 23 / 35 | ||
| 23 | PIRRO, Michele | Ducati Test Team | 2:03.105 | 2.691 | 0.099 | 33 / 35 | ||
| 24 | BAZ, Loris | Forward Racing Team | 2:03.316 | 2.902 | 0.211 | 28 / 37 | ||
| 25 | NAKASUGA, Katsuyuki | Yamaha Factory Test Team | 2:03.337 | 2.923 | 0.021 | 24 / 43 | ||
| 26 | DE ANGELIS, Alex | Octo Ioda Racing Team | 2:03.966 | 3.552 | 0.629 | 8 / 45 | ||
| 27 | MELANDRI, Marco | Aprilia Racing Team Gresini | 2:04.000 | 3.586 | 0.034 | 29 / 42 |