Hello, I am completely new here and hope that my contribution is right here. I recently added a Kreidler Florett City 50 4T as a craft project. Since I was interested in learning from screwing, little to no idea, I searched through forums and various videos. I added the scooter with a conrod bearing damage and broken valve, ergo also smashed piston. Have the engine ( GY6 139QMA/QMB ) completely apart All engine seals were also renewed. New cylinder, new cylinder head (but with shorter valves than before) new control chain, new control chain rail, new camshaft. Everything in 50ccm. In principle everything was completely renewed inside the engine. I also installed a new CDI and new alternator because I noticed that the old two cable blanks were sharpened. Now to the problem: The scooter jumps sup If I let the scooter turn on the main stand everything works, as soon as the rear wheel touches the ground it does not come from the spot. I give gas but it does not start by itself. If I push it with my feet and give it gas, it slowly accelerates but I come to 30Km/h at the highest and then it ends. For me it feels like the engine is really going to speed but the power is lost somewhere. Has possibly j request a tip for me where the problem might lie? LG