SEI MARINE PRODUCTS- Yamaha Water Pump Kit 6H4-W0078-A0 40 50 HP 2 Stroke 1984-1994 Without Housing This water pump kit replaces OE#: 6H4-W0078-A0 and fits 40 HP ( 1984-1994), and 50 HP ( 1986-1994) Yamaha outboard lower units. It does not include the housing.