Yamaha Water Pump Gasket 6E5-44315-AO

Genuine Yamaha Water Pump Gasket 6E5-44315-A0 – Lower Unit Cooling Seal
Ensure a watertight seal in your cooling system with the Genuine Yamaha 6E5-44315-A0 Water Pump Gasket. This precision-cut gasket is a critical component of your outboard's water pump assembly, sitting directly between the wear plate and the lower unit housing. Its primary job is to prevent high-pressure water from leaking out of the pump base, ensuring that every drop of cooling water is pushed up into the engine block where it is needed most to prevent overheating.
The Yamaha 6E5-44315-A0 is manufactured from a high-density, marine-grade material designed to withstand intense water pressure and extreme temperature cycles. Unlike generic gaskets that can saturate and blow out under pressure, this OEM Yamaha part is engineered to maintain its structural integrity and thickness. This provides a reliable seal that prevents the "pressure drop" that often leads to overheating alarms during high-RPM operation.
Using the correct gasket is one of the most overlooked parts of a water pump rebuild. This specific 6E5-series gasket is a direct fit for a massive range of Yamaha’s most popular mid-range and high-horsepower outboards. It is compatible with Yamaha V6 2-stroke models from 150hp to 250hp, early F200 and F225 4-stroke units, and the VMAX and HPDI series ranging from 150hp through 300hp high-performance models.
Whenever you drop your lower unit for an impeller change, this gasket must be replaced. Even if the old one looks intact, it has been compressed and heat-cycled, meaning it will not provide a reliable seal a second time. This genuine Yamaha gasket ensures perfect pressure retention for the impeller and provides a barrier that prevents saltwater from sitting between the pump plate and the aluminum housing, which stops the "white powder" corrosion that can seize your lower unit components.
For a professional installation, ensure the mounting surface on the lower unit is scraped completely clean of any old gasket residue or salt buildup. We recommend installing this gasket dry or with a very light coating of a non-hardening gasket sealer. Avoid using thick RTV silicone, as it can squeeze into the water passages and cause a blockage. Always torque your water pump housing bolts to factory specs in a criss-cross pattern to ensure even pressure across the entire gasket surface.

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