Overview

The Attwood Marine 3881KIT-1 is a service kit for the 3881-1 thru-transom scupper assembly. It replaces the wear parts at the outside face of the drain, including the outer ring, rubber flapper, and mounting screws, so an existing scupper can be refreshed without changing the original hose connection or transom cutout.

This kit fits the Attwood 3881-1 scupper used with 1-1/2 inch I.D. hose and a 2 inch installation hole. It is a practical fix when the flap has gone stiff, split, or stopped closing flat against the outlet, which can let water wash back into the cockpit or splashwell.

On boats where the main thru-hull body is still in good shape, this kit handles the parts that see the most weather and movement at the transom. It makes the most sense for routine maintenance on an above-waterline drain rather than a full replacement of the complete scupper assembly.

Key features

• Service kit for the Attwood 3881-1 thru-transom scupper assembly
• Fits the scupper assembly used with 1-1/2 inch I.D. hose
• Matches the 2 inch installation hole used by the 3881-1 assembly
• Includes replacement outer ring, rubber flapper, and four stainless steel screws
• Restores flap action at the transom outlet to help limit backwash into the boat

Compatibility and fit

This kit is meant for owners who already have the Attwood 3881-1 scupper in place and need to renew the external service parts. It does not replace the full thru-hull body or hose connection, so it is best used when the installed fitting is still secure and the main issue is at the flap or outer face.

Because the matching scupper assembly is an above-waterline transom drain, this kit suits cockpit and splashwell drainage points where water needs to exit freely and the flap needs to close back against the outlet after flow stops.

Installation and upkeep

Installation is straightforward for a like-for-like service job on an existing 3881-1 setup. Before fitting the new parts, it is worth checking that the mounted scupper body is not cracked and that the hose connection inside the hull is still sound. If those parts are damaged, the full assembly will need attention rather than only the service kit.

This is a good match for seasonal maintenance on boats that stay outside, run in rough water, or see frequent washdowns at the stern, where the flap and outer trim ring tend to wear first.

What’s included

• Outer ring
• Rubber flapper
• Four stainless steel screws