From the sounds of it, to me it sounds like the heat gets to the carb and evaporates the fuel. Does it work/start when you put some fuel down the car opening? RTR engines commonly do this in my experience, not that there is anything wrong, but its just how they are designed - or not designed enough!
If you could spray some compressed air over the carb closest to the engine to cool it off - champ drivers did this when their engines flamed out in a race.
Car-less (Velox V10 or 733) // RB T10.5"+" (JB Modified) // Bluebird BMS-990DMG (St) & BMS-631 (T/B) // ATS 16% // Capricorn Wheels // Protoform
"70% of the time, it works ALL the time"