hey i got a 2001 kx125 i hadgot it re cromed, new piston , rings, seals, ect when i put it back together and got it runiing it had no torque when i gas on it and when i was riding then about 4 hours l8r it blew up. do u no whats wrong??????

Was the bottom end rebuilt?

What actually blew up!! top end, bottom end? What were the plug reads while breaking it in like?

sounds like you were running really lean. adjust the fuel-air mix so its a little richer... ya know, after you rebuild the engine:)