Lower Unit Gear Oil Pump – Fits Mercury/Mariner, Johnson/Evinrude, Yamaha, Suzuki Outboards
This universal marine lower unit gear oil pump is designed for filling or re-filling outboard and sterndrive lower units with fresh gear lube. It connects to standard quart bottles with 28mm cap threads and includes multiple high-quality metal adapter fittings to service most major outboard and sterndrive brands.
Engineered for reliability, the pump features a 10cc per stroke capacity for precise, clean, and efficient oil changes. It directly replaces common aftermarket pumps, including JLM MARINE, Slippery Pete, and LOZAGU models, offering a versatile tool for any marine mechanic's kit.
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Universal Fitment: Includes 3/8"-16, M8, and M10 adapters for Mercury, Yamaha, Johnson/Evinrude, Suzuki, and more.
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Efficient Operation: Hand-operated pump with a 10cc per stroke capacity ensures controlled gear oil transfer.
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Versatile Design: Comes with two different length suction tubes to accommodate various quart bottle heights.
Compatible Engine Models
Confirm your engine model/year in the table below. For Mercury owners, here’s a guide to help you identify your engine’s serial/model: Mercury Serial Number Guide. You can also review exploded diagrams to verify part numbers: Mercury Parts Diagrams & Catalog.
For Johnson/Evinrude owners, here’s a guide to help you identify your engine’s serial/model: Johnson/Evinrude Serial Number Guide.
For Yamaha owners, here’s a guide to help you identify your engine’s serial/model: Yamaha Serial Number Guide. You can also review exploded diagrams to verify part numbers: Yamaha Parts Diagrams & Catalog.
For Suzuki owners, You can review exploded diagrams here to verify part numbers: Suzuki Parts Diagrams & Catalog.
| 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 |
| 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 |
| 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 Specifications
| Specification |
Value |
| Product Type |
Lower Unit Gear Oil Pump |
| Installation |
Hand-operated manual pump |
| Connection |
28mm standard quart bottle threads |
| Housing Material |
Plastic with metal adapters |
| 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 |
Package Contents
- 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 Guide
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Preparation: Position the outboard or sterndrive vertically and place a suitable oil drain pan beneath the lower unit.
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Remove Plugs: Loosen and remove the upper (vent) and lower (drain) gear lube plugs, allowing the old oil to drain completely. Inspect the magnetic tip of the drain plug for metal shavings.
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Attach Pump: Screw the pump onto a new bottle of standard quart gear lube. Select the appropriate suction tube (long or short) for the bottle height.
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Connect Hose: Attach the correct metal adapter to the pump hose and screw it into the lower drain plug opening.
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Fill Unit: Pump the new gear lube into the lower unit. Continue pumping until fresh lube begins to flow out of the upper vent hole.
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Seal Unit: While keeping the hose attached, re-install the upper vent plug and tighten it securely.
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Final Step: Quickly remove the pump adapter from the drain hole and re-install the lower drain plug. Tighten it securely, being careful not to overtighten.
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Clean Up: Wipe away any excess oil and properly dispose of the used gear lube.
Troubleshooting & FAQ
How do I know which adapter to use for my engine?
The pump includes three adapters for broad compatibility. Use the 3/8-16 swivel adapter for Mercury/Mariner, MerCruiser, Johnson/Evinrude, and Force models. Use the 8mm-1.25 or 10mm-1.25 adapters for most Yamaha, Honda, Suzuki, Nissan, and Tohatsu outboards. Always test-fit the adapter by hand into the drain port before attaching the pump.
The pump doesn't fit my gear oil bottle. Why?
This pump is specifically designed for standard quart bottles with 28mm threads. It is not compatible with certain brands like RedLine oil, which use non-standard bottle threading. Please check your gear oil bottle before purchase.
How much oil does the pump move with each stroke?
The pump is designed to deliver approximately 8cc to 10cc of gear oil per stroke. This allows for a controlled and efficient filling process, preventing overfills and spills.
OEM vs. Aftermarket?
This listing is an aftermarket replacement part (not an OEM component). We build to OEM specifications using comparable-grade materials. Production is done in an ISO9002-certified facility, and each batch is inspected for consistent performance.
How fast do you ship and how much does it cost?
We offer fast global shipping—typically 5–15 days worldwide—and standard shipping is free. Expedited options are available at checkout depending on your location.
What is your warranty and return policy?
This product includes a 1-year warranty against manufacturing defects under normal use. If something goes wrong, contact our support team with your order details. Returns are accepted within our standard return window (unused & in original condition); please see our policy page or reach out for instructions.
Important Notes
- Verify that the product images and specifications match your original part. If discrepancies exist—even if your model is listed—do not proceed with the purchase.
- This product is an aftermarket replacement part and is not an OEM component.
- Professional installation is recommended to ensure safety and optimal performance.
Why Choose JLM MARINE?
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Quality Assured: As a trusted manufacturer for over 20 years, we supply top marine brands globally.
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Fast Global Shipping: Free delivery worldwide in 5–15 days.
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Direct from Manufacturer: Competitive pricing without compromising quality.