Attwood 3876-3 Boat Self-Bailing Cockpit Mounted Scupper Valve Kit

Works great thanks

Flappers get deformed over time and let water flow back into boat. These high quality replacements are very easy to install (4 screws) and are exact OEM parts. I would recommend. First photo is replaced flapper and second photo is original deformed flapper.

These are perfect replacements for scuppers on Boston Whaler (94 Outrage). Kit comes with new plastic ring, rubber flap, rubber backing gasket ring, and four stainless screws. Easy to install, and they now fit flush. Just put a dab of 4200 on the screw hole to seal up the hole. Note on Whalers that they use two rings - the rear one raises off the hull surface slightly to clear the thru hull fitting. I was able to reuse four of the eight old rings to use as backing rings. If all your rings are cracked, you will need to order 2x as many kits to have enough rings.

Outside diameter 2 3/4”, the holes are 2 3/8” center to center. Ideally this would be for a scupper that measures 1 3/8” inside diameter or smaller, that is the size of the rubber “seat” that the flap will seal against. Product looked fine but returned it because it was too small for what I needed. Hopefully measurements will prevent more people from ordering just to find out the size .

Been driving around for the last few years with wet feet and wet everything else that touched the floor. Just sort of ignored it but finally replaced these and now have a perfectly dry boat floor. Been so long I honestly didn’t remember these work almost perfectly to keep every bit of water from flowing back into the hull so figured I’d just have a slight improvement with a little less water sloshing around but now no water at all! Best 15 minutes of boat work I’ve done yet!

i tried the fancy scuppers, and in the end they just don't last. i heard the ball ones can get clogged easy, are loud, and need to be at right level to work right. so i skipped trying that one. i did try the duckbill. it worked great at sealing and keeping water out. but due to the design, it didn't drain very fast. i didn't really like that. it would also clog at the littlest piece of anything. biggest problem was that it warped and deteriorated far too fast. since it's molded in a specific shape, once that shape is compromised it doesn't work very well. on this type, the flap is thick and doesn't warp very much(and is easily replaceable), it opens fully to drain at max flow, and it seals enough to keep water out. they may be low tech, but the standard flapper scupper is my preference.

Had to use shorter screws instead of the screws that were provided

allows water out fine ...but does not keep water from coming in in rough water , or backing up..have to put plugs in holes