Keep coolant and gear lube exactly where they belong with the Yamaha O-Ring – 93210-94003-00. Cut to a true 94 mm inner diameter with a 3 mm cross-section, this nitrile seal slips between the lower-casing drive and water-pump housing on a wide range of four-stroke V-6 and offshore V-8 models, including the 4.2 L “bullet” gearcase. One simple ring, but it’s the difference between a crisp-running pump and an overheated haul-out.

Compression-molded from fuel- and salt-resistant NBR rubber, the gasket stays pliable even after seasons of hot running, long lay-ups, and muddy ramp launches. Precision flash-trimmed edges hug the machined groove so you can torque the bolts once and walk away—no RTV mess, no second guesses.

Why this little ring matters

• Exact OEM dimensions – 94 × 3 mm profile seats perfectly; no trimming or stretching.

• Marine-grade NBR – shrugs off glycol, gear oil, and saltwater without cracking.

• Re-service friendly – lifts clean on teardown, sparing the housing from razor-blade scratches.

• Versatile fit – used in water-pump kits, lower-casing drive seals, and several 100-hour service packs.

Stash a couple in your spares box—because a two-dollar O-ring is cheaper than a cooked impeller and a ruined weekend.