Water Pump Housing O-Ring – Fits Yamaha 25HP 30HP 40HP 50HP 60HP (Replaces 93210-59MG7, 18-71334)

Product Details

This Water Pump Housing O-Ring is designed for Yamaha outboard and jet drive motors from 25HP to 60HP, covering models from 1995 through 2024. Engineered to fit the water pump adapter and lower casing drive assemblies, it ensures a proper seal to prevent water leaks and maintain cooling system integrity across a broad range of Yamaha engine configurations.

This aftermarket o-ring directly replaces Yamaha OEM 93210-59MG7, Sierra 18-71334, and GLM 84305, delivering equivalent fit and function at a competitive price.

• Manufactured from durable rubber with strong sealing properties for wear resistance and long service life
• Direct replacement design simplifies installation—remove the old o-ring and install the new one in minutes
• Compatible with both outboard and jet drive configurations across multiple model years

Part Number Matrix

Use this matrix to confirm equivalent references across OEM and aftermarket.

Engine & Model Compatibility

Confirm your engine model/year in the table below.

Technical Specs

Material

Rubber

OEM Reference

93210-59MG7

Compatibility

Yamaha 25HP, 30HP, 40HP, 50HP, 60HP outboard and jet drive engines

Application

Water pump housing seal

What's in the Box

• 1× O-Ring

Installation Notes

1. Disconnect the battery and allow the engine to cool completely before beginning work.
2. Remove the lower unit or water pump cover to access the housing assembly.
3. Carefully extract the old o-ring from the housing groove using a non-metal pick to avoid scratching the sealing surface.
4. Clean the groove thoroughly, removing any debris, corrosion, or old gasket material.
5. Lightly lubricate the new o-ring with marine grease to ease installation and ensure a proper seal.
6. Seat the new o-ring evenly in the housing groove, checking that it sits flush without twists or pinches.
7. Reassemble the water pump cover or lower unit, torquing fasteners to manufacturer specifications.
8. Reconnect the battery, run the engine on a flusher or in water, and inspect for leaks around the housing.

Troubleshooting & FAQ

How do I know if my water pump housing o-ring needs replacement?

Signs include visible water leaks around the lower unit or pump housing, overheating, reduced cooling flow from the tell-tale, or visible cracking and deformation of the existing o-ring during inspection.

Can this o-ring be used on both outboard and jet drive models?

Yes. This o-ring is compatible with Yamaha outboard and jet drive configurations from 25HP to 60HP, as listed in the compatibility table.

Should I replace other water pump components at the same time?

It is recommended to replace the impeller, gaskets, and seals as a complete kit during water pump service to ensure optimal performance and prevent premature failure.

Will this o-ring fit older Yamaha models from the 1990s?

Yes. Compatibility extends back to 1995 models and continues through current production engines, provided the model is listed in the compatibility table.

What happens if the o-ring is installed twisted or pinched?

A twisted or pinched o-ring will not seal properly, leading to coolant leaks, air ingestion, and potential overheating. Always ensure the o-ring is seated evenly in its groove before reassembly.

Do I need to apply sealant to the o-ring?

No. The o-ring creates a mechanical seal through compression. Use only a light coating of marine grease for lubrication during installation—never use adhesive sealant on o-rings.

OEM vs. Aftermarket?

This listing is an aftermarket replacement (not OEM). Built to OEM-level specifications with comparable materials. Manufactured in an ISO 9002 facility, batch-inspected for consistency.

Shipping speed & cost

We ship worldwide quickly—typical transit 5–15 days. Standard shipping is free; expedited options appear at checkout where available.

Warranty & returns

Covered by a 1-year warranty against manufacturing defects under normal use. If issues arise, contact support with your order details. Returns are accepted within our standard window (unused & in original condition). See our policy page or reach out for instructions.

Safety & Important Info

• Verify images/specifications against your original part. If anything differs—even if your model appears compatible—do not purchase.
• This is an aftermarket replacement, not an OEM component.
• Professional installation is recommended for safety and performance.

About Sea Sierra

• Pro-Grade Standards — We supply marine parts engineered to OEM-level tolerances and tested for real-world conditions.
• Fast Global Fulfillment — Free standard delivery to most regions in 5–15 days.
• Manufacturer-Direct Value — Fair pricing without compromising on materials or QC.