This was done on a 150cc scooter 50cc scooter should be the same process.
Affilate link https://www.ebay.com/sch/i.html?_from=R40&_trksid=p2334524.m570.l1313&_nkw=150cc+gasket+set&_sacat=0&LH_TitleDesc=0&_odkw=1997+f150+transmission+speed+sensor&_osacat=0&mkcid=1&mkrid=711-53200-19255-0&siteid=0&campid=5338081398&customid=&toolid=10001&mkevt=1