Aluminum cylinder head with large combustion chamber suitable for Minarelli AC 70cc cylinder kit by NARAKU (Part Number: NK100.31) and & CPI & Keeway cylinder kit (NK101.47)also suitable for other 70cc cylinders with 47mm bore. The larger combustion chamber will solve the electric start issues due to the higher compression on the bore kits. Needs spark plug with long thread like NGK E-type.