I'm new to the whole motorized bike hobby and built my first one this Sunday, May 2nd, and ever since have been maintaining it and using it daily. Earlier today I was riding it as normal until I heard some loud metal click and started to lose power. I could still use it but it eventually died when I had to turn a corner and the back tire locked up. Had to carry it back home and opened the cylinder head to see that the piston had seized up. I took off the cylinder to reveal some deep scratches on the piston itself and the rings split open from whatever scratched it and it's impossible to move it up and down. Didn't lock up because of a lack of lubrication but the crankcase is definitely locked up. Checked the G-rings to see if any had come out and everything was in tack. I'm still confused as to what debris went inside that had caused this damage? I'm currently running a 16:1 ratio, no modifications to the engine, everything is completely stock and it ran perfectly until it locked up and seized. What I'm mainly looking for is potentially a refund if at all possible or at least some replacement parts although having to split the case open and repairing it is outside my expertise and wouldn't seem worth the time, money, and labor to fix it up if it's going to come near the cost of what I paid for ($230 for the whole kit). Here is what the piston looks like. Looks horrible in my opinion.