4x Lower Unit Drain Plug Gasket 311598 for OMC Johnson Evinrude 18-4248

Product Overview

Lower unit drain and fill plug gasket set for OMC, Johnson and Evinrude outboards and sterndrives, supplied as 4 gaskets. It replaces OMC and Johnson Evinrude 311598, OMC sterndrive and Volvo Penta 3852105, and crosses to Mallory 9-60408 and Sierra 18-4248. The gasket seals the drain and fill screws on the gearcase, from the 20-35 HP two-cylinder crossflow engines up to the 3.0 litre V6.

These washers are the cheapest part on the gearcase and the one most often left out, which is why so many lower units come back with oil weeping down the skeg. They are a crush washer: once the screw has been torqued the gasket takes a set and has to be replaced, not reused. Four in a pack covers a drain and a fill screw on two services.

Specifications & Attributes

OEM Cross Reference

Compatible Engines

What's Included

Condition & Warranty

Before You Buy

• Check the drive or engine model, these gaskets cover the OMC gearcases and the OMC sterndrive that became Volvo Penta
• Fit a new gasket every time the screw comes out, a reused crush washer will weep
• Clean the screw head and the seat before fitting, grit under the gasket is the other cause of a leak
• Fill from the bottom drain hole until oil runs out of the top vent, then fit the top screw first
• Check for oil at both screws after the first run, a weep shows within a few miles
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