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Sierra Fuel Pump Kit 18-7811
The Sierra 18-7811 Fuel Pump Kit is a rebuild kit designed for Mercury and Mariner inline 6-cylinder 2-stroke outboards. This kit restores proper fuel delivery by replacing worn diaphragms and internal components in mechanical fuel pumps.
Fitment Overview
This Sierra kit replaces Mercury OEM part numbers 66599A1 and 89031A1, along with GLM 40350 and Mallory 9-37756. These part numbers identify a fuel pump family used on Mercury inline-6 engines.
Compatibility
| Brand | Horsepower | Engine Type |
|---|---|---|
| Mercury | 90 HP | Inline 6-Cylinder 2-Stroke |
| Mercury | 115 HP | Inline 6-Cylinder 2-Stroke |
| Mercury | 140 HP | Inline 6-Cylinder 2-Stroke |
| Mariner | 90 HP | Inline 6-Cylinder 2-Stroke |
| Mariner | 115 HP | Inline 6-Cylinder 2-Stroke |
| Mariner | 140 HP | Inline 6-Cylinder 2-Stroke |
These engines use a mechanical diaphragm-style fuel pump associated with the 66599A1 / 89031A1 fuel pump assembly.
Example Model Applications
- Mercury 90HP inline-6 2-stroke models
- Mercury 115HP inline-6 2-stroke models
- Mercury 140HP inline-6 2-stroke models
- Mariner equivalent inline-6 models
These are typical applications. Always verify by matching your OEM part number.
Fits These Serial Ranges
This fuel pump kit is used across multiple Mercury inline-6 engine generations and does not follow a single serial-number break.
Important: Confirm compatibility by matching your existing fuel pump or OEM number to 66599A1, 89031A1, 18-7811, 40350, or 9-37756.
Need the alternate fuel pump kit for a different pump style?
View Pro Marine Fuel Pump Kit 115 (A3 Style)
Part Numbers and Cross References
| Type | Part Number |
|---|---|
| Sierra | 18-7811 |
| Mercury OEM | 66599A1 |
| Mercury OEM | 89031A1 |
| GLM | 40350 |
| Mallory | 9-37756 |
What This Part Is Used For
This kit rebuilds diaphragm-style fuel pumps by replacing worn internal components such as gaskets, valves, and diaphragms. It restores proper fuel flow and pressure to the engine.
- Rebuilds mechanical fuel pump assemblies
- Restores fuel pressure and delivery
- Helps eliminate fuel starvation issues
- Supports reliable engine performance
A failing fuel pump can cause hesitation, stalling, hard starting, or poor acceleration.
System Function and Connections
- System Type: Mechanical fuel delivery
- Pump Type: Diaphragm fuel pump
- Location: Engine-mounted fuel pump assembly
FAQ
What engines does this kit fit?
It fits Mercury and Mariner inline 6-cylinder 2-stroke outboards in the 90HP, 115HP, and 140HP range using the A1-style fuel pump.
What is the difference between this and the A3 kit?
This kit fits the A1-style fuel pump (66599A1 / 89031A1). Some engines use a different pump design that requires the A3 kit.
How do I confirm fitment?
Match your fuel pump number or OEM part number to the cross references listed above.
What are signs of a bad fuel pump?
Hard starting, fuel starvation, hesitation, or engine stalling.
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 (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 accepted within 30 days of delivery.
- Items must be new, unused, and in original packaging.
- Return authorization is required before sending items back.
Need help with a return or order question?
Contact Us
Phone: 941-721-3000
Searchable Part Numbers
18-7811, 66599A1, 89031A1, 40350, 9-37756, Sierra fuel pump kit, Mercury inline 6 fuel pump kit, Mercury 115 fuel pump rebuild kit
18-7811
40370
508429
66599A1
89031A1
9-37752
880596511
8M6001413
889323
Pro Marine Square Fuel Pump for Mercury and Mariner 30-300HP
The Pro Marine 14360P Square Fuel Pump is a premium aftermarket replacement for Mercury and Mariner outboards using the popular 14360-series mechanical fuel pump. It provides a direct-fit, dependable alternative to the genuine Mercury assembly across numerous carbureted, EFI and Optimax applications.
Complete Square Mechanical Fuel Pump
This listing is for the complete engine-mounted square fuel pump assembly. It is not only a diaphragm or internal rebuild kit.
The pump uses crankcase pressure pulses to draw fuel from the boat's fuel supply and deliver it to the carburetors, fuel reservoir, vapor separator or Optimax fuel system, depending on the engine design.
Pro Marine item: 14360P
Replacement type: Mechanical diaphragm fuel pump
Primary Mercury reference: 14360A78
Why Choose the Pro Marine Replacement?
A Pro Marine replacement part developed for the marine repair and replacement-parts market.
Replaces numerous Mercury 14360-series square fuel-pump revisions.
Replaces the complete square mechanical pump rather than only the internal diaphragm.
An economical alternative for customers who do not require a genuine Mercury-branded component.
Used on select Mercury and Mariner 30-300HP carbureted, EFI, DFI and Optimax engines.
Supplied by Pro Marine USA with technical fitment assistance available before ordering.
OEM & Cross Reference Numbers
Mercury revised this square fuel-pump assembly numerous times. Match one of the numbers below to the original pump or to the number shown in the Mercury parts catalog.
Mercury and Mariner Fitment Overview
This pump appears across many Mercury and Mariner engine families. Use the overview below to identify the general engine group, and then compare your engine serial number with the detailed fitment section.
| 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
The Pro Marine 14360P is commonly used on the following Mercury Optimax, Pro XS and XS engine families when the original engine calls for one of the listed OEM fuel-pump numbers.
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 information. The application should call for one of the listed 14360-series or related OEM numbers.
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 fuel filters, damaged fuel lines, air leaks, carburetor problems or other fuel-system faults. Diagnose the complete fuel system before replacing the pump.
Grouped Mercury Serial-Number Fitment
The serial-number ranges below are grouped where multiple horsepower or model families share the same catalog range. This keeps the information searchable without repeating identical serial ranges for every horsepower.
| 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 |
| 250, 275HP Verado and related models | Refer to OEM number and complete serial lookup | Catalog includes select production-specific applications |
| 300HP Pro Max and XS | 0T409000 through listed 1B-series ranges | Select 3.0L Pro Max and 3.2L XS applications |
Mercury catalog applications can differ by production country, engine configuration and serial break. Use the complete serial number and confirm that the parts catalog specifies one of the OEM numbers shown on this page.
Prefer the Genuine Mercury Fuel Pump?
The Pro Marine 14360P is the primary replacement featured on this page. Customers who prefer a genuine factory Mercury component can select the OEM version below.
Genuine Mercury Square Fuel Pump Kit
Genuine Mercury fuel-pump assembly for customers who prefer a factory OEM component. Match OEM number 14360A78 or one of its listed superseded references before ordering.
View Genuine Mercury PumpPro Marine vs. Genuine Mercury
| Feature | Pro Marine 14360P | Genuine Mercury |
|---|---|---|
| Complete square fuel pump | Yes | Yes |
| Direct replacement application | Yes | Yes |
| Pro Marine branded part | Yes | No |
| Factory Mercury-branded component | No | Yes |
| Value-focused replacement option | Yes | Factory OEM option |
Frequently Asked Questions
Is this a Pro Marine product?
Yes. Item 14360P is a Pro Marine-branded premium aftermarket replacement fuel pump.
Is this a complete fuel pump?
Yes. This is the complete square mechanical fuel-pump assembly, not only a diaphragm or rebuild kit.
Does this replace Mercury 14360A78?
Yes. Pro Marine 14360P is an aftermarket replacement for Mercury 14360A78 and the other listed superseded and cross-reference numbers.
Will this fit every Mercury 30-300HP outboard?
No. The 30-300HP range describes the combined application coverage. Fitment depends on the engine model, configuration, serial number and OEM fuel-pump number.
Why is the serial number important?
Mercury frequently used different components within the same horsepower and model family. The engine serial number identifies the exact production range and is more reliable than horsepower alone.
Does this fit Mercury Optimax engines?
It fits the listed Optimax, Pro XS and XS applications that call for one of the OEM fuel-pump numbers shown on this page.
Is the genuine Mercury version available?
Yes. Use the Genuine Mercury product card above to view the factory OEM version.
The Pro Marine Advantage
Pro Marine supplies marine professionals, repair facilities, dealerships and boat owners with replacement engine parts for Mercury, Yamaha, Suzuki, Johnson, Evinrude and other leading marine brands.
Pro Marine replacement parts are selected to provide dependable fitment, practical value and reliable service for the marine repair market.
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.
- 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
Pro Marine 14360P, 14360P, 14360A14, 14360A15, 14360A16, 14360A24, 14360A27, 14360A41, 14360A43, 14360A53, 14360A66, 14360A69, 14360A71, 14360A78, 14360T75, 15930A21, 98766-C1, 98766C1, 99357A4, 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
14360A53
14360A66
14360A69
14360A71
14360A78
14360T75
15930A21
98766-C1
98766C1
99357A4
8M0103289
883202T02
883202T1
888733T1
14307T
14307T01
143071
8M0047624
8M0240950
8558432
883306
8M0118177
8M0141827
881862T
881862T08
892874T01
899106T01
