hey dude i got a 07 pitster pro 125x3r which has a GPX125 and for the last 2 years its been sick, im 6foot 4 and weigh 91kgs and it hammers with me on it, i chucked on a 146cc ceramic bore kit g3 cam and a new cdi after i had it a while and ive never had any problems and its goes hard, the mods were pretty cheap, all up about $500 if i remember right, good luck brother