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