Keeway 50ccm, built in 2007 – no longer starts after air filter change

Hello dears, I have a problem with my Keeway scooter, built in 2007, 50ccm, throttled to 25km/h. Until the day before yesterday everything was ok. Then he started to jerk and didn’t want to go up the mountain like that anymore. I looked and saw that the air filter was over. The seal and the mat inside hung only in shreds. So new LF ordered and installed. But now nothing more! It just doesn’t start. So: – carburettor dismantled and completely cleaned – spark plug rub nigt – Ignition spark is present – Is there a spray drive – Excess fuel left out of the carburetor (was due to the many steps in it ) Now I am at the end with my Latin. Does anyone have any idea what this might be about? I am grateful for every suggestion