China Roller 4 measure Sachs 49er or Rex RS 450 does not start

Hello, I have already checked/changed the following with my China Roller, Sachs 49er Bj2006, but the GUTE still does not want to start: – Ignition spark was not available at first. The trigger was the ignition coil, which I changed. Ignition spark now there. – Ignition spark is also new. A NGK CR7HSA – carburetor is new, when trying to start petrol comes through the petrol hose – I have set the valves inlet 0.05 mm and outlet to 0,10 mm – Compressio result 10 bar and therefore io. fuel is also sucked in, the compression tester also got petrol in the test – the scooter stood four years, the fuel I renewed Despite all efforts, the good one so far gives no sign of life. Only 1x short when I had given some fuel manually into the spark plug opening, followed by spark plug and plug on it and started. However, the aha experience stopped only for about 2 sec and the scooter is again Do you have any advice for me on what else that can be?