DT125R FORUM

According to the previous owner it has not been skimmed or re bored, I also haven't done this to it, i had been running it fine the way it was for 7 months or so then one day it just went, like any 2 Stoke does when it pops. So took the head and barrel off, no scoring at all in the barrel but the piston definetly hit something and the power valve has a bit of scoring on it so it must had caught it, I have no idea how this happend but I have heard if it's not set properly it can spin right round and come to far for the piston to strike it.
Thanks for your reply mate

@Calum
No mate the barrel is still the same as before, the powervalve has been set to open for the time being

@CYBER-NINJA

Yes pal, I had the head and barrel off the engine to change piston and gaskets, I changed the piston and top end baring etc hooked her back up and it had a knocking noise coming from it In bolted the barrel leaving the He's attached and changed the top end baring, the piston felt a little more tight on the con rod at this point, I put the head back on bolted her back up and still knocking noise coming from it double checked every bolt that had been loosend, they were all ok BUT they were not torqued up with a torque wrench
Thanks for your reply mate

I recently just top end rebuilt my 2003 DTR 125, power valve somehow shot out a bit to far one day and caugh the piston, but its firing up now and driving but when at low revs there's a knocking sound coming front the head? I changed the top end baring and it's still the same, any suggestions much appreciated thanks