Yamaha Water Pump O-Ring – Replaces 93210-59MG7 / Sierra 18-71334

Product Details

This water pump O-ring is a single replacement sealing ring for the Yamaha water pump assembly. It is identified as a replacement for Yamaha OEM part number 93210-59MG7 and Sierra part number 18-71334. The O-ring helps seal the water pump components and maintain cooling-system water flow when correctly matched to the engine and pump assembly.

This listing is for the O-ring only. It does not include the water pump housing, cover, impeller, gasket, key, bolts, or any other water pump components.

• Single water pump O-ring replacement
• Replaces Yamaha OEM reference 93210-59MG7
• Cross-reference: Sierra 18-71334
• For use in the water pump assembly when the original part number matches
• Verify the exact engine model, year, serial range, and pump diagram before ordering

Part Number References

The following references identify the same O-ring application in the available product and catalog records. Part-number references do not replace model-specific fitment verification.

Compatibility Information

Catalog documentation identifies this O-ring as part of the water pump kit application for Yamaha F30 models from 2013–2017 and F40A models from 2008–2017. Because Yamaha fitment can vary by model designation, year, serial range, and water pump configuration, use the OEM number and the engine's parts diagram to confirm compatibility before purchase.

Important: Do not assume that every Yamaha 25HP, 30HP, 40HP, 50HP, or 60HP engine uses this O-ring. Confirm the complete model designation, year, serial range, and the water pump diagram for your engine.

Technical Specifications

Product type

Water pump O-ring

Quantity

1 O-ring

Material

Rubber sealing ring

Yamaha OEM reference

93210-59MG7

Sierra reference

18-71334

Application

Yamaha water pump assembly

What's in the Box

• 1× Water pump O-ring

No housing, cover, impeller, gasket, key, bolts, or complete water pump kit is included.

Installation Notes

1. Allow the engine to cool completely and follow the manufacturer's safety procedures before beginning work.
2. Remove the required lower-unit or water-pump components to access the O-ring location.
3. Remove the old O-ring with a suitable non-metal pick, taking care not to scratch the sealing groove or mating surface.
4. Clean the groove and mating surfaces thoroughly. Remove dirt, corrosion, and remnants of the old seal.
5. Lightly lubricate the replacement O-ring with a suitable marine grease if permitted by the service instructions.
6. Seat the O-ring evenly in its groove. Make sure it is not twisted, stretched, pinched, or displaced.
7. Reassemble the water pump components using the manufacturer's tightening sequence and torque specifications.
8. Run the engine using the appropriate flushing equipment or in water and check for proper cooling-water flow and leaks.

Troubleshooting & FAQ

What does this listing include?

This listing includes one water pump O-ring only. It is not a complete water pump repair kit and does not include an impeller, housing, cover, gasket, key, bolts, or other seals.

What part numbers does this O-ring replace?

The documented references are Yamaha 93210-59MG7 and Sierra 18-71334. Confirm that one of these references matches your original part or engine parts diagram.

Will it fit every Yamaha 25HP through 60HP engine?

No universal horsepower-range claim should be assumed. Yamaha water pump parts vary by model, year, serial range, and configuration. Verify the exact engine information and OEM reference before ordering.

How can I tell if the old O-ring needs replacement?

Replace the O-ring if it is cracked, flattened, hardened, cut, swollen, permanently deformed, or damaged during water pump service. Water leakage around the pump assembly can also indicate a sealing problem, although other damaged components may produce similar symptoms.

Should I replace the impeller at the same time?

If the water pump is being serviced, inspect the impeller, wear plate, gaskets, key, housing, and cover. Replace any worn or damaged components according to the engine manufacturer's service instructions.

Can sealant be used on the O-ring?

Do not apply adhesive sealant unless the engine manufacturer's service instructions specifically require it. Use only a compatible lubricant in a light coating when recommended, and ensure the O-ring is seated correctly.

Is this an OEM part?

This listing is for an aftermarket replacement O-ring. Yamaha 93210-59MG7 is provided as the OEM reference number for identification and fitment checking.

Safety & Important Information

• Verify the original part number and complete engine model before purchase.
• Keep model, year, serial range, and water pump configuration together when checking compatibility.
• Do not use this O-ring if its dimensions or profile differ from the original component or parts diagram.
• Follow the manufacturer's service manual for disassembly, lubrication, torque values, and testing.
• Professional installation is recommended when lower-unit or water-pump service procedures are unfamiliar.

About Sea Sierra

• We provide replacement marine components identified by OEM and aftermarket reference numbers.
• Each listing is intended to help you match the replacement part to the correct engine application.
• For the best result, compare the part number and engine parts diagram before ordering.