The item "Head assembly Delta 110 cc" is a cylinder head for Delta mopeds. The head closes the cylinder from above and forms the combustion chamber; it houses the valves, camshaft and spark plug port.
Replace it if the valves have burned, there are cracks, the guides and seats are worn, or compression is lost. When installing, replace the gasket and tighten the nuts in a crisscross pattern. Head assembly with valves, camshaft and covers.
