This exhaust valve is installed in the cylinder head of the host engine. It controls the release of combustion gases from the cylinder into the exhaust manifold, opening and closing in time with the camshaft to maintain proper cylinder scavenging and intake-charge efficiency. A worn or burned valve seat causes compression loss, reduced power, and hard starting. This component is manufactured to the original geometry and material specification, matching the seat angle and stem clearance required for correct sealing without adjustment. On reinstallation, the valve stem seal should be replaced and the valve clearance set to the engine specification.