Lower Unit Gear Lube Oil Pump – Fits Mercury Outboard, Yamaha, Honda & MerCruiser Sterndrives (Replaces 26-830749, 8M0204693)
Lower Unit Gear Lube Oil Pump – Fits Mercury Outboard, Yamaha, Honda & MerCruiser Sterndrives (Replaces 26-830749, 8M0204693) is backordered and will ship as soon as it is back in stock.
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Worry-free returns
Worry-free returns
You may return most new, unopened items within 7 days of delivery for a full refund. We'll also pay the return shipping costs if the return is a result of our error (you received an incorrect or defective item, etc.).
You should expect to receive your refund within four weeks of giving your package to the return shipper, however, in many cases you will receive a refund more quickly. This time period includes the transit time for us to receive your return from the shipper (5 to 10 business days), the time it takes us to process your return once we receive it (3 to 5 business days), and the time it takes your bank to process our refund request (5 to 10 business days).
If you need to return an item, simply login to your account, view the order using the "Complete Orders" link under the My Account menu and click the Return Item(s) button. We'll notify you via e-mail of your refund once we've received and processed the returned item.
Delivery and Shipping
Delivery and Shipping
Free standard shipping on all orders under 1 KG
Lower Unit Gear Lube Oil Pump – Fits Mercury Outboard, Yamaha, Hond...
Product Details
This Lower Unit Gear Lube Oil Pump is designed for easy gear oil changes on a variety of marine engines. It is compatible with most Mercury outboards, MerCruiser sterndrives, and many models from Yamaha, Honda, and Suzuki that use a standard quart bottle with a 28mm opening.
It serves as a direct replacement for Mercury OEM part numbers including 26-830749 and 8M0204693.
- Manual hand pump for controlled fluid transfer, delivering approximately 8cc per stroke.
- Fits standard quart gear lube bottles with a 28mm threaded opening.
- Includes 3/8", 8mm, and 10mm metal adapters to fit various lower unit drain/fill plugs.
Part Number Matrix
Use this matrix to confirm equivalent references across OEM and aftermarket.
| Brand | Part Number |
|---|---|
| Mercury | 26-830749 |
| Mercury | 8M0204693 |
| Mercury | 830749 |
Engine & Model Compatibility
Confirm your engine model/year in the table below.
This pump is designed for broad use with most Mercury outboards and MerCruiser sterndrives. It is also suitable for many Yamaha, Honda, and Suzuki models, though specific model-year data is not available. This kit is not compatible with Volvo Penta lower units.
| Brand | Model | Rated HP | Stroke | OEM Part No. |
|---|---|---|---|---|
| Mercury | F30-F400 Series | 30-400 | 4-Stroke | 26-830749, 8M0204693 |
| Mercury | D75-D300 Series | 75-300 | 26-830749, 8M0204693 | |
| Mercury | E150-E250 Series | 150-250 | 26-830749, 8M0204693 | |
| MerCruiser | Multiple Sterndrive Models | 26-830749, 8M0204693 |
Technical Specs
- Product Type
- Lower Unit Gear Lube Oil Pump
- Installation
- Manual hand pump
- Connection
- Fits standard quart bottles with 28mm opening
- Housing Material
- Plastic with aluminum adapters
- Housing Color
- White/clear with metal adapters
- Weight
- Approx. 113-150g (4-5.3 oz)
- Fitting Type
- 3/8" swivel, 8mm and 10mm metal adapters
- Thread Size
- 3/8", 8mm, 10mm
- Output
- 8cc per pump stroke for some models
What’s in the Box
- 1 x Lower Unit Gear Lube Oil Pump Assembly
- 1 x 3/8" Swivel Adapter
- 1 x 8mm Metal Adapter
- 1 x 10mm Metal Adapter
- 2 x Rigid Suction Tubes (13cm, 15cm)
- 1 x Cap Adapter (for 28mm bottle opening)
- 1 x Flexible Clear Fill Tube
- 2 x Drain Gasket (for Mercury/Mercruiser models)
Installation Notes
- Place a suitable drain pan under the lower unit of your engine.
- Remove both the lower drain/fill screw and the upper vent screw from the gearcase assembly.
- Allow all of the old gear oil to drain completely. Inspect the old oil for any metal shavings or milky appearance.
- Screw the appropriate adapter (3/8", 8mm, or 10mm) snugly into the lower drain hole.
- Attach the pump assembly to a fresh bottle of manufacturer-recommended lower unit gear lubricant.
- Connect the pump's flexible fill tube to the adapter installed in the gearcase.
- Pump the new lubricant into the lower unit until a steady stream of new oil flows out from the upper vent hole.
- Keep pressure on the pump and reinstall the upper vent screw to create a vacuum seal.
- Quickly remove the fill tube and adapter from the bottom hole and reinstall the lower drain/fill screw.
- Tighten both screws to the manufacturer’s specified torque. Do not overtighten.
- Clean any excess lubricant from the gearcase exterior and dispose of the old oil properly.
Troubleshooting & FAQ
Will this pump fit my specific engine?
This pump is designed for broad compatibility with Mercury, MerCruiser, Yamaha, Honda, and Suzuki lower units. It includes 3/8", 8mm, and 10mm adapters to fit the most common drain plug sizes. Please verify your engine's drain plug size before purchase. Note: It is not compatible with Volvo Penta models.
How do I know which adapter to use?
The kit includes multiple adapters to fit common drain plug threads. Gently test-fit the adapters by hand into your lower unit's drain plug opening to find the correct size before attaching the pump assembly.
The pump isn't drawing oil from the bottle. What's wrong?
First, ensure the suction tube is securely attached and fully submerged in the gear oil. Check that the pump's cap is screwed tightly onto the quart bottle to create a proper seal, as any air leak will prevent it from priming. Finally, confirm there are no cracks in the pump housing or tubes.
What is the difference between this pump and an OEM version?
This aftermarket pump is engineered to meet or exceed OEM specifications for fit, function, and material quality but is offered at a more accessible price. It is built for reliable performance and includes multiple adapters for wide utility across different brands.
How much oil does this pump move per stroke?
This pump is rated to deliver approximately 8 cubic centimeters (cc) of fluid per full, steady stroke. This allows for controlled and efficient filling without creating air pockets.
Can this pump be used for other fluids like engine oil?
This pump is specifically designed for filling lower unit gearcases with marine-grade gear lubricant, which is typically a high-viscosity oil. It is not recommended for use with engine oil, gasoline, solvents, or other volatile chemicals.
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 vs 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.
Payment & Security
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