Overview

The Jabsco 18777-0001-P is a neoprene impeller kit for marine flexible impeller pumps that use a 10-blade rotor with a 2-1/4 in. diameter, 2 in. width, 5/8 in. shaft size, spline drive, and brass insert. Those dimensions are the key fit points on a boat, because they determine how the impeller seats in the pump bore and how the hub engages the shaft.

This profile is commonly used in raw-water cooling pumps and related water-moving pump setups where the original impeller matches the same dimensions and spline style. It is also associated with Jabsco 50410, 22110, and 23800 series crankshaft-driven pumps, so it is a practical service part for many inboard installations where pump access is tight and a correct spare matters.

Key features

• 10-blade neoprene impeller for pump applications that match this blade count and profile
• 2-1/4 in. outside diameter and 2 in. width, which are critical measurements when matching an existing impeller
• 5/8 in. shaft size with spline-drive hub for compatible marine pump shafts
• Brass insert at the hub for the impeller profile used in this kit
• Useful as a scheduled service part and as a spare kept on board for raw-water pump maintenance

Compatibility and fit

Use this kit where the old impeller matches the same outside diameter, width, shaft size, blade count, and spline-drive hub. That check matters more than engine brand alone, especially on older boats or repowered boats where pump history is not always clear.

For engine cooling service, a close dimensional match helps the pump prime correctly and maintain water flow without stressing the cover plate, cam, or shaft. If your current impeller has swollen, torn vanes, or a damaged hub, compare it before disposal so you can confirm the replacement profile against the pump in hand.

Installation and service

When you fit a new impeller, inspect the pump cover and internal wear surfaces for grooves or scoring before closing the pump back up. A damaged cover face can cause poor prime or small air leaks that are easy to miss until engine temperature starts to climb.

Wet or lubricate the new impeller during installation so the vanes are not starting dry on first spin-up. On boats that run regularly, this is the sort of spare worth keeping in the engine room, particularly for coastal cruising, fishing boats, and small auxiliaries where a failed raw-water impeller can end the day quickly.