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18-7808
18-7808
40330
40330
508427
55278A2
55278A2
55278A5
55278A5
9-37750
Genuine Mercury Square Fuel Pump for Mercury and Mariner 30-300HP
This genuine Mercury square mechanical fuel pump is used on numerous Mercury and Mariner carbureted, EFI, DFI and Optimax outboards. It is the factory OEM option for applications calling for 14360A78 or one of the listed superseded Mercury fuel-pump numbers.
Genuine Mercury Fuel Pump Assembly
This listing is for the complete engine-mounted square mechanical fuel pump, not only a diaphragm or rebuild kit.
The pump uses engine crankcase pressure pulses to draw fuel from the boat's fuel system and deliver it to the carburetors, fuel reservoir, vapor separator or Optimax fuel system, depending on the engine configuration.
Brand: Genuine Mercury Marine
Part type: Mechanical diaphragm fuel pump
Primary OEM reference: 14360A78
Why Choose Genuine Mercury?
Manufactured and supplied as a genuine Mercury Marine replacement part.
Designed for Mercury and Mariner applications specified in the factory parts catalog.
Replaces the complete square mechanical fuel-pump assembly.
Appropriate for owners and technicians who prefer an original Mercury-branded component.
OEM & Superseded Part Numbers
Mercury revised this square fuel-pump assembly numerous times. Match one of the numbers below to the original pump or to the number listed in the Mercury parts catalog.
Mercury and Mariner Fitment Overview
This fuel pump appears across many Mercury and Mariner engine families. Use the overview below to identify the general application group, then verify the engine serial number and OEM pump number.
| Engine Family | Common Applications |
|---|---|
| 30-60HP | Select 2-cylinder, 3-cylinder, 4-cylinder, Jet and BigFoot Mercury and Mariner models |
| 65-125HP | Select 3-cylinder, 4-cylinder, 6-cylinder, Jet, Marathon, SeaPro, EFI and Optimax models |
| 135-200HP | Select V6 carbureted, EFI, XR6, Magnum, Marathon, SeaPro and Optimax models |
| 225-300HP | Select V6, EFI, DFI, Optimax, Pro Max, Pro XS, Marathon and SeaPro models |
Common Mercury Optimax Applications
This square mechanical pump is commonly used on the following Mercury Optimax, Pro XS and XS engine families when the factory parts catalog specifies one of the OEM numbers listed above.
3-cylinder, 2004-2014
3-cylinder, 2006-2014
3-cylinder, 2004-2014
1.5L 3-cylinder, 2004-2014
1.5L 3-cylinder, 2006-2012
3.0L 6-cylinder, 1997-2002
3.0L 6-cylinder, 1998-2006
3.0L, 2004-2018
3.0L, 2006-2018
3.0L, 1998-2005
3.2L, 2006-2017
Important Fitment Note
Mercury used several square fuel-pump revisions across engines with the same horsepower. Horsepower or model year alone is not enough to confirm fitment.
Match the OEM number on the original pump or verify the complete engine serial number in the detailed fitment section below.
What This Fuel Pump Does
The square mechanical fuel pump uses pressure pulses from the engine crankcase to move fuel through the outboard's low-pressure fuel system.
Depending on the engine design, the pump may supply fuel directly to the carburetors or feed a fuel reservoir, vapor separator or Optimax fuel system.
Possible Symptoms of a Weak Fuel Pump
- Hard starting or extended cranking
- Engine stalls shortly after starting
- Fuel starvation under load
- Hesitation during acceleration
- Loss of power at higher RPM
- Engine runs better while the primer bulb is manually pumped
- Fuel leakage around the pump or diaphragm housing
These symptoms can also result from restricted filters, damaged fuel lines, air leaks, carburetor problems or other fuel-system faults. Diagnose the complete system before replacing the pump.
Grouped Mercury Serial-Number Fitment
Serial ranges are grouped where multiple horsepower or model families share the same catalog range. This keeps the information searchable while reducing repeated entries.
| Engine Models | Serial Number Range | Catalog Notes |
|---|---|---|
| 30, 40HP 3-cylinder | 0G590000 through 0G760299 | Select USA production models |
| 40, 50HP 3-cylinder | 0G760300 through 0T979999 | Select USA and Belgium production models |
| 50, 55, 60HP 3-cylinder | 0G590000 through 0T979999 | Includes listed standard, BigFoot and Jet applications |
| 45, 50, 55, 60 Jet | 0G590000 through 0T979999 | Select USA and Belgium Jet models |
| 65, 75, 90HP 3-cylinder | 0D283222 through 0G960499 | Select carbureted and early production applications |
| 75, 80, 90, 115, 125HP Optimax | 0T178500 and later listed production ranges | 1.5L 3-cylinder DFI and Optimax models |
| 100, 115, 125HP | 0G960500 through 1B226999 | Select 4-cylinder, EFI and related applications |
| 135, 150, 175, 200HP V6 | 0G960500 through 1B226999 | Select carbureted, EFI, XR6, Magnum, Marathon and SeaPro models |
| 200, 225HP Optimax | 0G960500 through 1B417701 | Select 3.0L DFI and Optimax production ranges |
| 225, 250HP Pro XS | 1B226999 through listed later production ranges | Select 3.0L Pro XS applications |
| 300HP Pro Max and XS | 0T409000 through listed 1B-series ranges | Select 3.0L Pro Max and 3.2L XS applications |
Mercury applications can differ by production country, engine configuration and serial break. Confirm that the factory catalog specifies one of the OEM numbers listed on this page.
Looking for the Pro Marine Replacement?
The genuine Mercury pump is the factory OEM option. The Pro Marine 14360P below provides the same application coverage as an economical Pro Marine-branded replacement.
Pro Marine Square Fuel Pump – 14360P
Pro Marine-branded replacement for the listed Mercury 14360-series fuel pumps. A direct replacement option for customers seeking dependable fitment and practical value.
View Pro Marine Fuel PumpGenuine Mercury vs. Pro Marine
| Feature | Genuine Mercury | Pro Marine 14360P |
|---|---|---|
| Complete square fuel pump | Yes | Yes |
| Direct replacement application | Yes | Yes |
| Factory Mercury-branded component | Yes | No |
| Pro Marine-branded component | No | Yes |
| Best suited for | Customers preferring OEM | Value-focused replacement |
Frequently Asked Questions
Is this a genuine Mercury part?
Yes. This is the genuine Mercury Marine square mechanical fuel-pump assembly.
Is this a complete fuel pump?
Yes. This is the complete square fuel-pump assembly, not only an internal diaphragm or rebuild kit.
Does it replace Mercury 14360A78?
Yes. This pump corresponds with 14360A78 and the other listed superseded Mercury part numbers.
Will it fit every Mercury 30-300HP outboard?
No. The horsepower range represents combined application coverage. Fitment depends on the engine model, configuration, serial number and OEM pump number.
Why is the engine serial number important?
Mercury frequently used different components within the same horsepower family. The serial number identifies the engine's exact production range.
Is a Pro Marine replacement available?
Yes. Pro Marine 14360P is available as an economical replacement. Use the product card above to view it.
Dealer Discounts & Store Policies
Dealer / Marine Industry Discounts
Are you a marine dealer, technician, boat builder, or industry professional? We offer dealer pricing for qualified marine businesses.
Shipping Policy
- Free shipping on orders over $100 in the continental U.S.
- Orders ship via UPS, USPS and FedEx.
- Orders received before 5:30 PM EST ship the same business day.
- Typical delivery time is 1-5 business days.
30-Day Return Policy
- Returns are accepted within 30 days of delivery.
- Parts must be new, unused and in their original packaging.
- Installed parts are not returnable.
- OEM electrical parts are not returnable.
- Return authorization is required before sending items back.
Need help confirming fitment or have an order question?
Contact Us
Phone: 941-721-3000
Searchable Part Numbers & Applications
14360A78, 14360A14, 14360A15, 14360A16, 14360A24, 14360A27, 14360A41, 14360A43, 14360A53, 14360A66, 14360A69, 14360A71, 14360T75, 15930A21, 98766-C1, 98766C1, 99357A4, genuine Mercury square fuel pump, Mercury mechanical fuel pump, Mercury pulse fuel pump, Mariner square fuel pump, Mercury Optimax fuel pump, Mercury Pro XS fuel pump, Mercury 30HP fuel pump, Mercury 40HP fuel pump, Mercury 50HP fuel pump, Mercury 60HP fuel pump, Mercury 75HP fuel pump, Mercury 90HP fuel pump, Mercury 115HP fuel pump, Mercury 125HP fuel pump, Mercury 150HP fuel pump, Mercury 175HP fuel pump, Mercury 200HP fuel pump, Mercury 225HP fuel pump, Mercury 250HP fuel pump, Mercury 300HP fuel pump
14360A15
14360A16
14360A24
14360A27
14360A41
14360A43
14360A71
14360A78
99357A4
40280
42909A1
42909A2
42909A3
42909A4
600-125-03
15930A2
3 Cylinder
75hp 1.5L Optimax
80hp 1.5L Optimax
90hp 1.5L Optimax
115hp 1.5L Optimax
125hp 1.5L Optimax
115hp Pro XS
6 Cylinder
200hp 3.0L Optimax
200hp 3.0L Pro XS
225hp 3.0L Optimax
225hp 3.0L Pro XS
250hp 3.0L Optimax
250hp 3.0L Pro XS
300hp 3.0L Optimax
300hp 3.0L Pro XS
888725T1
888725T1
8M0118177
8M0141827
881862T
881862T08
892874T01
899106T01
888733T1