Compatible With: For GY6 49cc 50cc 80cc 100cc CVK Carburetor Carb Main Jet 139QMB139QMA. Thread: M4. - Quantity and size: the carb main nozzle kit has a total of 15 pieces, the size includes40,44,46,48,50,52,54,56,58,60,65,70,75,80,85.