A valve seal prevents oil from entering the combustion chamber past the valve stem, and it is important to replace them because worn seals lead to oil consumption, smoke formation, and reduced engine performance.
Cylinder Head Bolt for Yanmar 3TNV88 and related engines. OEM 129150-01200. Price per piece — a complete 3TNV88 head gasket requires 14 bolts. Always replace during head gasket change!