Lower Unit Gear Oil Pump – Fits Mercury/Mariner, Johnson/Evinrude, Yamaha, Suzuki Outboards (Replaces Various OEM Adapters)

$15.99 $25.00

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Lower Unit Gear Oil Pump – Fits Mercury/Mariner, Johnson/Evinrude, Yamaha, Suzuki Outboards (Replaces Various OEM Adapters) is backordered and will ship as soon as it is back in stock.

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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

Free standard shipping on all orders under 1 KG

If you have any questions, feel free to email us at info@sierramarines.com, and we’ll get back to you within 20–36 hours.

Product Details

This universal marine Lower Unit Gear Oil Pump is designed for easily filling or refilling gearcase oil in most major outboard and sterndrive lower units. It connects directly to standard 28mm quart gear lube bottles and includes multiple adapters to fit Mercury, Mariner, Johnson, Evinrude, Yamaha, Honda, Suzuki, and more.

It serves as a direct functional replacement for other aftermarket pumps, including the JLM MARINE, Slippery Pete, and LOZAGU models.

Simple hand-operated pump delivers 10cc of fluid per stroke for controlled filling.
Includes a flexible 19.5-inch hose for reaching fill ports in tight spaces.
Comes with 3/8-16, 8mm, and 10mm metal adapters to service most marine engines.

Part Number Matrix

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

Brand	Model/Reference
JLM MARINE	Lower Unit Gear Oil Pump
Slippery Pete	Lower Unit Gear Oil Pump
LOZAGU	Lower Unit Gear Oil Pump

Engine & Model Compatibility

Confirm your engine model/year in the table below.

For all Mercury, Mariner, Force, and MerCruiser models, use the included 3/8-16 steel swivel adapter.

Brand	Model	Rated HP	Stroke	Years	Notes
Mercury	All Outboards	All	2 & 4-Stroke	All	Uses 3/8-16 adapter
Mariner	All Outboards	All	2 & 4-Stroke	All	Uses 3/8-16 adapter
MerCruiser	All Sterndrives	N/A	N/A	All	Uses 3/8-16 adapter
Force	All Outboards	All	2-Stroke	All	Uses 3/8-16 adapter

For Johnson, Evinrude, and OMC models, use the included 3/8-16 steel swivel adapter.

Brand	Model	Rated HP	Stroke	Years	Notes
Johnson	All Outboards	All	2 & 4-Stroke	All	Uses 3/8-16 adapter
Evinrude	All Outboards	All	2 & 4-Stroke	All	Uses 3/8-16 adapter
OMC	All Outboards	All	2 & 4-Stroke	All	Uses 3/8-16 adapter

For Yamaha, Honda, Suzuki, Nissan, and Tohatsu models, use either the 8mm or 10mm adapter fitting as required.

Brand	Model	Rated HP	Stroke	Years	Notes
Yamaha	All Outboards	All	2 & 4-Stroke	All	Uses 8mm or 10mm adapter
Honda	All Outboards	All	4-Stroke	All	Uses 8mm or 10mm adapter
Suzuki	All Outboards	All	2 & 4-Stroke	All	Uses 8mm or 10mm adapter
Nissan	All Outboards	All	2 & 4-Stroke	All	Uses 8mm or 10mm adapter
Tohatsu	All Outboards	All	2 & 4-Stroke	All	Uses 8mm or 10mm adapter

Technical Specs

Product Type: Lower Unit Gear Oil Pump
Installation: Hand-operated manual pump
Fuel Type: N/A - For gear oil only
Connection: 28mm standard quart bottle threads
Housing Material: Plastic with metal adapters
Housing Color: Black/Clear
Dimensions: 19.5 inch (495 mm) hose length; pump body approximately 6 inches (152 mm)
Weight: 170 g (0.37 lb)
Fitting Type: Multiple adapters included
Thread Size: 3/8-16 swivel, 8mm-1.25, 10mm-1.25 adapters
Working Pressure: Hand pump (8cc/10cc per stroke)
Other Technical Attributes: Features both long (6.125 inch/156 mm) and short (4.75 inch/121 mm) suction tubes for different bottle heights

What’s in the Box

1 x Lower Unit Gear Oil Pump Assembly
1 x 3/8-16 Swivel Steel Adapter
1 x 8mm-1.25 Male x 3/8-16 Female Adapter
1 x 10mm-1.25 Male x 3/8-16 Female Adapter
1 x Long Suction Tube (6.125 inch/156 mm)
1 x Short Suction Tube (4.75 inch/121 mm)
1 x Clear Plastic Hose (19.5 inch/495 mm)

Installation Notes

Position the outboard or sterndrive in the vertical (down) position.
Place a suitable drain pan under the lower unit.
Slowly remove the upper (vent) and lower (drain/fill) plug screws. Inspect magnetic screw ends for metal debris.
Allow all of the old gear oil to drain completely. This may take several minutes.
Select the appropriate length suction tube for your oil bottle and securely attach the pump assembly.
Attach the correct adapter fitting (3/8-16, 8mm, or 10mm) for your engine to the end of the clear hose.
Firmly insert and thread the adapter into the lower drain plug hole.
Pump the new gear oil into the lower unit until you see fresh oil begin to flow out of the upper vent hole.
Reinstall the upper vent plug screw first, ensuring its washer is in good condition.
Quickly remove the pump adapter from the lower hole and reinstall the lower drain plug screw.
Tighten both plug screws to the manufacturer's recommended torque. Do not overtighten.
Properly dispose of the used gear oil according to local regulations.

Troubleshooting & FAQ

Which adapter do I use for a Mercury/Mercruiser engine?

Use the 3/8-16 swivel steel adapter for all Mercury, Mariner, MerCruiser, and Force sterndrive/outboard models.

My Yamaha outboard doesn't fit the 3/8-16 adapter. Which one is correct?

Most Yamaha, Honda, Suzuki, and Tohatsu outboards use either the 8mm-1.25 or 10mm-1.25 adapter, both of which are included in this kit.

Will this pump fit any quart bottle of gear lube?

The pump is designed for standard 28mm threaded quart bottles. It is known to be incompatible with the non-standard threading on RedLine oil bottles.

How much oil is transferred with each pump?

The pump has a capacity of approximately 8cc to 10cc per full stroke, allowing for precise control when filling the gearcase.

Why does the kit include two plastic suction tubes?

Two tubes of different lengths (6.125" and 4.75") are included to ensure the pump can reach the bottom of various short and tall style quart bottles.

My pump isn't drawing oil, what's wrong?

Ensure the pump body is securely tightened onto the gear oil bottle to create a proper seal. Also, confirm the suction tube is fully submerged in the fluid and that all hose connections are tight.

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.

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