Well... since last weekend my Garelli has been fucked up... it does not run. At first I believed it was just because no fuel was flowing because my petcock knob fell off and i could not turn the fuel on. I fixed this by using a screw to fill for the missing knob. It did not solve the problem. Now the engine started up... but it only ran for about 5 seconds then shut down completely on me. Any answers to why my moped will not run? It has a new spark plug, carb. was cleaned recently, and other misc. work was done at it. It worked then, not it doesnt. I need help!