Most people racing seriously these days are going for the 4 stroke 250f's as generally the likes of the yz125 have to race against the 4 stroke 250cc bikes in the lites class. They just are not as competitive. You also have the problem that not all manufacturers are making the 2 stroke 125cc any longer. So I suggest you look at the yz250f if Yamaha is the bike you like. My son races the crf250r at an elite level and we have had no problems with that bike