Overview

The Jabsco SK890 is a service kit for rebuilding the 50890 series single diaphragm waste pump. It replaces the service parts around the diaphragm chamber and flow path, including the diaphragm, cover, joker valves, ports, and the related fasteners and washer.

This is the practical repair option when the installed 50890 series pump still has a serviceable motor and mounting setup, but the pump-side wear parts need attention. The 50890 pump uses 1-1/2 in (38 mm) hose connections, and this kit includes the two replacement ports used in that layout.

On boats with a sanitation system that already depends on the 50890 series pump, this kit helps you rebuild the parts most likely to be opened during service without replacing the full pump.

Key features

• Fits Jabsco 50890 series waste pumps with the single diaphragm design.
• Replaces the main service items in the diaphragm chamber and valve path rather than only one wear part.
• Includes two pump ports for the 1-1/2 in (38 mm) connection size used on the 50890 pump.
• Suited to a pump rebuild when the service parts need replacement but the motor assembly does not.
• Useful for planned maintenance or for restoring an existing pump already installed in the boat’s sanitation system.

Compatibility and fit

This kit is for the Jabsco 50890 series waste pump with the single diaphragm layout. It matches the service-kit items shown for that pump family and covers the pump-side components, not the separate motor assembly.

Before ordering, check the pump series on the installed unit, especially on boats that have had sanitation parts changed over time. This is a series-specific rebuild kit, not a universal Jabsco waste pump repair kit.

Installation and service

Service work should be done with power disconnected and the pump isolated from the system. On the 50890 pump, the hose layout uses 1-1/2 in (38 mm) non-collapsible waste hose, and airtight suction-side connections matter for pump performance after reassembly.

This kit makes sense during routine pump service, hose replacement, or a sanitation system inspection when the diaphragm and valve parts are already being checked. It is a good fit for boats that rely on the 50890 series pump and need a straightforward rebuild of the serviceable pump components.

What’s included

• 1 cover
• 1 diaphragm
• 4 hex head screws
• 1 recessed pan head screw
• 1 washer
• 2 pump joker valves
• 2 pump ports