7 years of service life: Gilera Runner 50 starts very bad or not at all

Hello guys, sorry, this is probably the 9347 thread on the topic, but it is always individual again. So: my runner 50 C14 BJ 1998 doesn’t start with the kick starter, no matter how long and intense I step (the battery is empty and thus the electric start is not possible). The scooter stood about 7 years. I managed to start it with a pinch of brake cleaner in the air filter box, however the next attempt hit a few minutes later (without brake pure). My plan: clean carburettor. Makes sense at all, because the scooter was running with the help of the brake cleaner before?! What else could you do good for an old scooter? My plan was: -new brake pads front -new brake fluid -new oil fill in -new air filter -motul fuel system cleaner fill (unnecessary?) -possibly change coolant -possibly new spark plug -possibly a new carburettor, if everything does not help (costs at Ebay only about 30€) -Tires are from 2005 :// Anything else? I would like to make the scooter again with relatively little money and effort. Thanks for your help !