ok i have some friends that are saying there 125s can beat my YZ 250 . my YZ is completely stock , there bikes are a little upgraded and stuff . but i still think my bike would win . what type of bikes WOULD beat a YZ 250 2 stroke?  

Beat it how?  In a straight drag race? On a MX track? In the woods? With a stick? On a supercross track?

Truth is with dirt bikes a lot of whats faster depends on the rider.  If your friend is really fast on a 125; he could easily beat a slow poke like me. (I make a better mechanic than a racer) But he would have a lot harder time keeping up with a more experienced rider like Pinit.  (It's true Pin, I've seen the videos)

If your talking straight out power the most souped up 125, heck lets say bored out to 150 like the rules say they can be now, will not be as powerful as a stock 250.  And it will be harder to ride.  When it comes to Power there is no replacement for displacement.  

I used to run a KX 125 bored out to a 144cc and just switch to a 05 YZ 250.  No comparison like night and day brother.  

I have recently beat a 92 cr 250 and a 99 cr 125 on my 03 cr85r all i have is a full fmf exhaust system. i dont know what it is about my lil pinger but it out runs all i come across im 5'8" 125lbs this thing screams!!  

firelizard:
I have recently beat a 92 cr 250 and a 99 cr 125 on my 03 cr85r all i have is a full fmf exhaust system. i dont know what it is about my lil pinger but it out runs all i come across im 5'8" 125lbs this thing screams!!

You are either a very special rider, or something is seriously wrong with those other bikes.