YAMAHA VALVE SEAL K0A-A3722-00

Function and technical context

The K0A-A3722-00 valve seal is a critical sealing component in the engine timing system, installed in the cylinder head to prevent oil leaks around the valve stem. This seal acts as a physical barrier between the combustion chamber and the engine crankcase, preventing lubricating oil from escaping into the intake or exhaust duct. Its deterioration allows lubricant leakage, which reduces system pressure, causes abnormal oil consumption and can affect engine performance and the durability of other critical components.

When to replace this part?

Common symptoms of seal failure include visible oil loss around the cylinder head, increased lubricant consumption between changes, bluish smoke in the exhaust, or carbon deposits on the valves. It is recommended that these components be inspected during each seasonal maintenance and replaced preventively if moisture or leakage is detected, especially after prolonged periods of inactivity. Changing the seal preventively avoids major problems such as valve damage, loss of compression or oil contamination, avoiding costly repairs at sea.

Equivalent manufacturer part numbers