Jabsco 890-0000 Pump Gasket, 11860/6050/777 Series

This is the genuine Jabsco 890-0000 gasket, the thin seal that sits between the cover plate and the pump body on Jabsco's Self-Priming 11860, 6050, and 777 Series pumps. It's a gasket only. No cover plate, no screws, no impeller. Just the one part that almost always gets chewed up the moment you crack the pump open for service.

If you've ever pulled the cover plate off a flexible impeller pump, you know how this goes. The old gasket sticks to one face, tears as it lets go, and comes off in pieces. Nobody gets it off clean. And once a gasket has been compressed and heat-cycled a few seasons, it's flattened hard and it won't seal properly a second time. That's why a fresh gasket goes on anytime the cover plate comes off. It's cheap insurance against a job you'll otherwise be doing twice.

So what happens when the gasket is tired? On a self-priming pump the cover plate seal matters more than people think. A weeping gasket lets the pump pull air in around the cover plate on the suction stroke, and a pump that's sipping air is a pump that won't hold its prime. You'll see it as a slow loss of prime after shutdown, a pump that takes forever to catch, or a steady drip and salt creep around the edge of the cover. Chase an overheat alarm on a raw-water cooling pump and more often than not you're into the impeller and this gasket anyway.

This part is aimed at anyone doing routine service on these Jabsco self-priming pumps. That's the spring recommissioning crowd pulling the impeller before splash, the folks winterizing in the fall, and anybody tracking down a cooling or transfer pump that's lost its grip. If you run one of these pumps, buy the gasket with the impeller and do them together. You don't want the pump apart on the bench and realize the one flat part you need is still at the chandlery.

Fitting it is straightforward. Get the mating surface on the pump body and the inside of the cover plate genuinely clean first. Scrape off every scrap of the old gasket and any hardened residue so the new one seats flat, because a bit of old material trapped under the new gasket is its own slow leak. Lay the fresh 890-0000 in place, set the cover plate on, and start all the screws by hand before you snug anything down. Then tighten in a cross pattern, a little at a time, so the plate pulls down evenly. Don't lean on it. Over-torquing a flexible impeller pump cover warps the plate and ruins the seal you're trying to make, which is the opposite of what you want. Snug and even beats cranked down hard every time. Check your pump's service manual for whether it calls for the gasket dry or with a light sealant, since that's set by the pump, not the gasket.

One honest note on scope. This is the gasket and nothing else. If your impeller is worn, cracked, or has lost a vane, you need the impeller too, and that's a separate part. The gasket alone won't fix a pump that's down on flow because of a bad impeller. Think of the 890-0000 as what makes the repair seal up right, not the whole repair. For a lot of boaters the smart move is to keep a couple of these in the spares box so there's always one aboard when the pump comes apart.

Fitment is the Jabsco Self-Priming 11860 Series, 6050 Series, and 777 Series pumps. Before you order, read the model number stamped on the pump body and confirm it falls in one of those series. Jabsco builds a wide range of pumps and the cover gaskets aren't all the same shape, so matching the series is what keeps you from fighting a seal that was never going to fit. Get the right gasket, clean the surface, snug it down evenly, and the pump goes back together and holds like it should.