DT125R FORUM

makes sense. I saw a man on Instagram and he said that sparkplug lost the ceramic

https://www.instagram.com/reel/DBgjJzjN5um/?igsh=MWRjODliaG9vN25sMA==

I bought the big bore but I'm afraid to put it on and the same thing will happen

What could be causing the piston to be like this? The connecting rod has no clearance upwards and to the sides.