My moped starts but then it dies right after

@geeman760 there could be a lot of reasons for that but I suggest that you start looking at the carburetor. If you have a stuck needle valve in the float bowl, your moped starts but immediately starves and dies because of not getting more fuel. Verify the exact year and make and model of your moped so we can be sure to find the right settings etc. for your moped.

I agree that it sounds as if there is a fuel shortage. Please check that air is able to go into the top of the fuel tank -this replaces the fuel as it is used. If the air hole is blocked, usually by polish, a partial vacuum is created above the fuel, causing the engine to stop.