hi my name is zach. i have a 03 rm125 that wont idle. i know that it shouldnt be the top end because i put a new 1 in myself at the beginning of winter. it has a wiesco piston, v force reeds, hot rod crank, and a alumnium cylinder head. it supposidly has a "over sized carb" but i have never heard of that. i just got it before the winter and it wouldnt idle when it was hot. it soon had low compression and wouldnt start so i took off the cylinder head to find the piston being eaten away. i put a new top end in it and it started 4th kick. it allways starts 1st kick now. i think that it has some sort of powervalve modd. it has amazind top end bugt absolutely no low end before like 8 thousand rpms. my friends race 450s and they say that it has more than normal power. it aalso has full fmf. the guy i bought it from said that it was a 144. this kid was not informed with motocross. when i put the new piston it was stock or at least i think it was. anyways it wont idle right. it will start easy and idle really high when it is cold but when it heats up it keeps wanting to stall out. help. maybe old coolant it isnt working as efficantly.