My '79 Jag has a fuel problem. It starts and runs great, but after a while it will flood out and die to the point that there is gas coming out of the vent hole on the carburetor. It does this while idling or at a faster speed. I have cleaned all the carburetor parts and installed a new needle and seat, pilot jet, and floats. What else could it be? The coil and CDI are fine. The fuel pump is fine. The only other thing I can think of is that the choke plunger may not be seating all the way. I have a 9 year old boy that really, really wants to ride this sled without it dying on him all the time. Any ideas?