Hello, bear with me for a bit I am new to mopeds and 2 strokes in general. A little more than a month ago I bought a puch magnum with an e50 motor under it. It had a metra 65 kit on it, a dellorto sha 16:16 carb and a performance exhaust. It had no air filter either. Well at the time it wouldn't start easy but would start and run rather well. It progressively got harder and harder to start until it wouldn't. I did a compression test on it the othèr day and the readings were very low at 75psi, so I figured the rings were done for. They are and the piston and cylinder, so much scoring on bottom side of piston and the cylinder. So today I ordered the same kit to install. Does anyone have an idea what might have gone wrong? Play in connecting arm? To rich or lean? I know the lack of an air filter contributed to it as well if not for all of it. Piston installed upside down? Anyways I was curious about jetting as well. What jet would for a 16 16 would you all run on this moped and what spark plug as Well? It has a ngk b7hs on it currently. I want to apologize as well as I am uncertain as to whether i should post this in performance or the repair sections. Thanks allot