663W0078A000
About this part
This page covers the genuine Yamaha part 663W0078A000 (Water pump repair kit). It’s an original OEM component designed to match Yamaha’s factory tolerances for correct fit, reliable function, and long service life in marine conditions.
Why choose genuine Yamaha?
For marine use, OEM specification matters. Yamaha components are designed for salt, humidity, temperature swings, and continuous vibration. If you’re aiming for “fit once, do it right”, genuine parts are typically the safest option.
Notes for this part
Installation tip: inspect the wear plate and housing for scoring, and renew any O-rings or seals disturbed during disassembly. Avoid dry starts — ensure the leg is supplied with water before running.
Impellers are a key cooling-system service item. If the tell-tale is weak, cooling flow seems inconsistent, or you’re not sure when the pump was last serviced, replacing the impeller is sensible preventative maintenance.
Warranty
Warranty: 1 year on new genuine parts (subject to correct installation and normal use).
Ordering tips
Ordering tip: when buying multiple items, it’s worth reviewing the same diagram section for related gaskets and seals so everything arrives together.