Recently purchased a used a 2007 Vespa LX 50 with 2,500 miles. I had the carburetor cleaned, changed the fuel & vacuum lines and new batter. From a cold startup, the may turn off on first initial throttle and afterwards on the first couple of seconds, it struggles with power but after itís warmed up the issues go away. Could it be the carburetor jet dirty or a spark plug? Any help is appreciated!!!