Scooter 52mm 105cc Racing Cylinder Head Kit For Baotian BT49QT BT50QT GY6 50cc 139QMB 4T This cylinder head kit is designed for with 52mm bore and 105cc displacement.It is compatible with Baotian BT49QT, BT50QT, GY6 50cc, and 139QMB 4-stroke engines.The kit includes a cylinder head, gaskets, and necessary hardware for installation.It supports performance by improving airflow and combustion efficiency.The design allows for integration with standard engine components.Intended for use in racing or performance applications, it replaces the stock cylinder head to enhance engine output.