YAMAHA INTAKE GASKET 688-13621-A1

Function and technical context

The intake gasket is a critical component of the air distribution system on Yamaha outboard engines. This part hermetically seals the interface between the intake manifold and the cylinder head, ensuring that the air-fuel mixture reaches the combustion chambers in a controlled manner without leaks or water infiltration. Poor sealing in this area causes loss of intake pressure, entry of salt moisture into the combustion chamber, accelerated internal corrosion and loss of engine power, especially under load.

When to replace this part?

Deteriorated intake gaskets present symptoms such as difficulty starting when cold, unstable idle, abnormal vibrations during acceleration and the presence of water in the combustion chamber after periods of navigation in a saline environment. Although there is no fixed replacement interval, it is recommended to check its condition during each seasonal maintenance, especially if the engine has been idle or exposed to high humidity conditions. Replacing the gasket preventively when detecting the first signs of degradation avoids costly repairs due to internal corrosion and secondary damage to cylinders and pistons.

Equivalent manufacturer part numbers