When the 2013 MotoGP pilots ignite their perspective machines under the floodlight of Losail International Circuit in Qatar this week, much attention will be garnered by the reunited Yamaha Factory Racing team of Valentino Rossi and Jorge Lorenzo.The nine-time World Champion Rossi returns to the factory Yamaha team after two sour years with Ducati Team, joining his former teammate, two-time and reigning MotoGP Champion Lorenzo.And this Thursday marks another historical reunion date for Rossi and Lorenzo with the opening of the round 1 of 18 in 2013 MotoGP with the first free practice session at Doha, Qatar.Both riders have had much success at Qatar, including wins. Rossi, who spent the 2004-2010 MotoGP seasons aboard a factory Yamaha, which includes four titles, last won at Qatar in 2010. That was his third premier-class win at the 3.343-mile circuit containing 16 corners.The 34-year-old Italian has struggled the last two years aboard the Ducati, taking 7-10 finishes at Qatar in 2011/2012, but immediately showed his competitiveness aboard the Yamaha during preseason testing. Rossi even led one session at Jerez, and is looking to regain his rhythm at Qatar this weekend.Valentino Rossi (Yamaha Factory Racing YZR-M1 MotoGP) says: “I’m very happy with the work done in Jerez and over the winter. I was fast and everything worked fine and we have a competitive bike to fight for the podium.“I believe that in Qatar will not be so easy; it is a track that is a little difficult for me, but I think I can defend myself and get a good result. I would like to get on the podium: that’s my goal. After the testing I know I can be competitive in some tracks but also that I will have some problems in other tracks. The most important thing is that now I have a good feeling when I ride my M1 and this will help me at all tracks, including Qatar.“Every year you get a little bit nervous at the beginning of the season. It’s normal to feel like that; it’s crucial to get some good points and not to make mistakes. I can’t wait to start this 2013 season.”As for Lorenzo, he has nothing but luck at Qatar, never finishing off the podium across all classes. This includes his win last season by over 0.8 of a second ahead of Respol Honda duo of Dani Pedrosa and the now-retired Casey Stoner.Lorenzo also holds the fastest lap and best pole at the Qatar circuit – a 1:53.927 set during his rookie year in MotoGP aboard the Yamaha. The 25-year-old Spaniard has also been running up front throughout preseason testing, leading a session at Jerez.Jorge Lorenzo (Yamaha Factory Racing YZR-M1 MotoGP) says: “I am very excited to return to Qatar and begin the season. The testing has been good, we have good pace and we are quite happy with our performance. We still have some areas to improve but our situation is not so bad compared to our competitors and I think we can fight for the win.“Jerez was a good point for us after testing in Austin; that was a new circuit where maybe we haven’t yet found a perfect feeling. In Jerez we were able to make a long run and all the Yamahas were on top; that gave us some extra motivation before traveling to Qatar. It also shows that every track is different and it’s going to be an exciting Championship.“I want to keep the crown but it’s going to be hard. There are some great riders this year, I was surprised by Marquez’ pace and also with Valentino on his return to Yamaha. Dani is also so strong after the last part of the 2012 season. We will fight really hard from the first race, I believe we are in good shape for that.“Losail is a track where we usually find a difficult track surface, plenty of sand and because of that it is always very tough with the tires. We will see how we can perform there. I am feeling very fit and ready so I want to start!”Built in the desert on the outskirts of Qatar’s capital city Doha, the Losail International Circuit has hosted a MotoGP round since 2004. The track celebrated the first ever night-time Grand Prix in 2008 and continues to be the only night race on the calendar. The 3.343-mile track is well suited to the YZR-M1 with a fast flowing nature. With a main straight over a kilometer in length and a combination of medium and high-speed corners, the track is guaranteed to provide an exciting spectacle to start the season, Yamaha reports.