646-13621-00 Yamaha GASKET

Yamaha reed valve gasket component used in the intake manifold assembly of 2-stroke outboard motors. Seals the reed valve block to the intake passage, maintaining proper reed valve function and engine compression. Found in 40HP-50HP outboard class engines. Replacement required when intake manifold is serviced or when compression loss is diagnosed. Ensures smooth intake flow and prevents unmetered air leakage into combustion chamber.