rex 50 no longer running – Ignition

Hello. I searched for a long time, but found no threat. My ProbleM. I got a scooter (Rex Flash 50) from a friend who always went out in the rain. So I only drove in the dry. At some point I cleaned it with the pressure cleaner and then he didn’t go as usual. Coomic was just that he just jumped on when he was dry for a maybe 2 seconds and then didn’t go on. For weeks. Then I disassembled him and thought that he was looking for it. I bought a new ignition coil and because I wasn’t sure I had a new CDI unit. Then it was great. For two days. Now it’s exactly the same problem, with the new parts. Zündfunke immediately weaker, then completely gone… Can someone help me? Wouldn’t it be great? What could that be? Greeting Tim