A marine gear oil pump transfers lubricant from a quart bottle into an outboard’s lower unit through the drain opening. The Slippery Pete is best for boat owners who want multiple metal adapters and two bottle tubes; the LOZAGU pump is better for buyers who prioritize a stated 10cc-per-stroke output. SeaSierra emphasizes use with marine and automotive fluids, while Bentolin names several outboard brands. FEAOXYO is another option for buyers seeking a pump with three adapter sizes.
| Product | Best For | Notable Feature |
|---|---|---|
| Slippery Pete | Common lower-unit oil changes | Three adapters and two suction tubes |
| LOZAGU | Higher stated output per stroke | 10cc per stroke |
| SeaSierra | Marine and automotive fluid transfer | Three adapters and 28mm bottle fit |
| Bentolin | Named outboard adapter coverage | Brand-specific adapter descriptions |
| FEAOXYO | Multi-purpose fluid transfer | Three adapter sizes |
Slippery Pete Lower Unit Gear Oil Pump
Best for: Boat owners who want a pump kit with multiple lower-unit adapters for routine gear oil changes. The listed fittings are a 3/8-inch metal swivel, an 8mm metal adapter, and a 10mm metal adapter. The product pumps 8cc per stroke.
Two rigid suction tubes are included to reach the bottom of tall and short gear oil bottles. This can help reduce leftover oil in the container when the pump is used with a compatible standard quart bottle. The connected clear plastic tubing lets the user see the transfer line.
Why it was selected: Its adapter assortment and two tube lengths address common fit and bottle-reach considerations. Limitation: The listing says it is not compatible with Volvo Penta. Check the drain-plug size and bottle opening before buying.
LOZAGU Quart Bottle Gear Oil Pump
Best for: Buyers comparing pumps by stated fluid output per stroke. LOZAGU lists 10cc per pump stroke, higher than the 8cc-per-stroke figures listed for some other options here. The kit includes 3/8-inch swivel, 8mm, and 10mm metal adapters.
The pump is designed for standard quart bottles with a 28mm cap and includes a long 6.125-inch tube and a short 4.75-inch tube. These tube lengths are intended for tall and short quart bottles, respectively.
Why it was selected: The output specification and two tube lengths make it straightforward to compare with other quart-bottle pumps. Limitation: The listing says it will not fit Volvo Penta, and bottle compatibility depends on the 28mm opening.
SeaSierra Outboard Gear Lube Pump
Best for: DIY owners who want a pump described for both marine and automotive fluid transfer. SeaSierra lists use for outboard gear lube, automotive maintenance, and other fluid-transfer tasks.
It is designed for standard 32-ounce quart bottles with a 28mm neck. The included adapters are 3/8-inch, 8mm, and 10mm, which the listing describes as suitable for many standard marine and automotive applications. This makes it a flexible choice when the same pump may be used for more than one maintenance task.
Why it was selected: Its stated bottle size, three adapter options, and multi-purpose positioning make it a useful comparison for buyers who value versatility. Limitation: The listing does not specify pump output per stroke, so it is harder to compare filling speed from the provided information.
Bentolin Marine Gear Oil Pump
Best for: Buyers who want adapter descriptions tied to specific outboard brands. Bentolin lists a 3/8-inch-16 swivel for Mercury and Mariner outboards and other American-made outboards. Its 8mm-1.25 and 10mm-1.25 male adapters are listed for Yamaha, Nissan, Tohatsu, Honda, Johnson, Evinrude, and other foreign-made outboards.
The pump is listed at 8cc per stroke and includes two suction tubes for tall and short quart bottles. Its cap adapter is made for standard quart bottles with a 28mm opening.
Why it was selected: The detailed adapter descriptions can help buyers narrow their choice by motor brand and fitting size. Limitation: The listing says the adapters will not fit Volvo Penta. Confirm the opening size of your oil bottle as well as the motor fitting.
FEAOXYO Outboard Gear Oil Pump
Best for: Owners seeking a pump described for marine, automotive, and industrial fluid transfer. FEAOXYO lists use with boat engines, yachts, and car transmissions, along with oil changes, refills, and fluid extraction.
The kit includes a 3/8-inch metal swivel and 8mm and 10mm adapters. It is designed for standard 32-ounce bottles with a 28mm neck. The listing presents the adapters as a way to connect the pump to different engine or transmission fittings.
Why it was selected: Its multiple adapter options and stated multi-purpose uses give it a clear role among these choices. Limitation: The provided features do not state a per-stroke output or include tube-length details, so compare those points if transfer volume or bottle reach is a priority.
Buying Guide: How To Choose A Marine Gear Oil Pump
Will the pump fit your outboard?
Start with the lower-unit drain opening and its required adapter size. The products here list 3/8-inch swivel, 8mm, and 10mm options, but those sizes are not interchangeable. Check your motor’s requirements and the pump’s adapter details before ordering. Several listings specifically exclude Volvo Penta, so do not assume a pump will fit that brand.
Does the pump fit your gear oil bottle?
Many of these pumps are designed for standard quart bottles with a 28mm neck. Confirm the bottle opening rather than relying on volume alone: a 32-ounce bottle with a different neck may not attach as intended. If you use both tall and short bottles, look for a kit that lists two suction tubes.
How much oil does each stroke transfer?
A higher stated amount per stroke can mean fewer pumping strokes to move a given volume, but actual use depends on the setup. LOZAGU lists 10cc per stroke; Slippery Pete and Bentolin list 8cc per stroke. The SeaSierra and FEAOXYO feature details provided here do not specify output per stroke.
What should you check before starting?
- Verify the fitting size required by your outboard.
- Confirm that the pump cap matches the bottle neck.
- Choose a suction tube suited to the bottle’s height.
- Follow the motor and gear oil manufacturer’s service instructions.
Frequently Asked Questions
What does a lower-unit gear oil pump do?
It transfers gear lubricant from a bottle through a fitting into an outboard’s lower unit. The adapter connects to the motor’s oil opening.
Are 8mm and 10mm adapters interchangeable?
No. They are different sizes. Use the adapter that matches the motor’s specified fitting.
Do these pumps fit every quart bottle?
No. Several are designed for a standard quart bottle with a 28mm neck. Check the bottle opening against the product specifications.
Can these pumps be used with Volvo Penta?
Do not assume compatibility. Multiple product listings explicitly say their adapters do not fit Volvo Penta.
Which listed pump has the highest stated output per stroke?
LOZAGU lists 10cc per stroke. Slippery Pete and Bentolin list 8cc per stroke; output details are not provided for the other two products.