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Mercury Outboard Parts
Shop Mercury outboard motor parts by system, including cooling, fuel delivery, electrical, internal engine components, lower unit parts, and routine service items. Browse OEM and replacement Mercury marine parts to support maintenance, repair, and rebuild projects.
Shop by System
- Complete Powerheads
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- Cooling System
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- Electrical System
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- Fuel & Carburetion System
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Common Mercury Outboard Model References
This category supports many popular Mercury outboards across a wide horsepower range. Always confirm your model and serial number for best fitment.
- Portable & Midrange: 2.5HP–60HP (2-stroke & FourStroke)
- Performance: Pro XS and EFI platforms (75HP–300HP)
- Direct Injection: Optimax models (75HP–250HP)
- Premium Offshore: Verado models (135HP–400HP)
- Commercial: SeaPro models (commonly 75HP–300HP)
Always confirm your exact horsepower, model year, and serial number to ensure proper part compatibility before ordering.
18-7810
40390
40390
508432
9-37755
9-37755
90363A1
90363A1
Fuel Pump Kit 115
The Fuel Pump Kit 115 is a Pro Marine rebuild kit designed for Mercury and Mariner inline 6-cylinder 2-stroke outboards. This kit restores proper fuel delivery by replacing worn internal components in diaphragm-style mechanical fuel pumps.
Fitment Overview
This kit replaces Mercury OEM part numbers 66599A3 and 89031A3, along with Sierra 18-7813, GLM 40370, and Mallory 9-37752. These cross reference numbers identify the Mercury inline-6 fuel pump family used on 90HP, 115HP, and 140HP 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 share a common diaphragm-style fuel pump design tied to the 66599A3 / 89031A3 fuel pump assembly.
Example Model Applications
- Mercury 90HP inline-6 2-stroke models (late 1970s–1980s)
- Mercury 115HP inline-6 2-stroke models
- Mercury 140HP inline-6 2-stroke models
- Mariner equivalents using the same fuel pump assembly
These are typical applications for this fuel pump kit. Always verify by matching your OEM part number or fuel pump assembly before ordering.
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 66599A3, 89031A3, 18-7813, 40370, or 9-37752.
Using a different pump style? This engine family may also use an alternate A1-style kit.
View Sierra 18-7811 Fuel Pump Kit (A1 Style)
Part Numbers and Cross References
| Type | Part Number |
|---|---|
| Pro Marine | 115 |
| Mercury OEM | 66599A3 |
| Mercury OEM | 89031A3 |
| Sierra | 18-7813 |
| GLM | 40370 |
| Mallory | 9-37752 |
What This Part Is Used For
This kit rebuilds mechanical diaphragm fuel pumps by replacing worn internal components such as diaphragms, gaskets, and valves. Proper fuel pump operation is essential for maintaining consistent fuel delivery to the engine.
- Restores proper fuel pressure and flow
- Replaces worn diaphragms and seals
- Helps eliminate fuel starvation issues
- Supports smooth engine performance
A failing fuel pump can cause hard starting, hesitation, loss of power, or engine stalling.
System Function and Connections
- System Type: Mechanical fuel delivery system
- 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 this fuel pump style.
What is the difference between this and the A1 kit?
This kit fits the A3-style fuel pump (66599A3 / 89031A3). Some engines use a different pump design that requires the A1-style 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, poor acceleration, fuel starvation, 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
115 fuel pump kit, 66599A3, 89031A3, 18-7813, 40370, 9-37752, Mercury inline 6 fuel pump rebuild kit
18-7811
18-7813
40350
40370
508429
66599A1
66599A3
89031A1
89031A3
9-37752
9-37756
18-7812
40360
508430
66599A2
89031A2
9-37751
18-7809
40340
40340
508428
55278A3
55278A3
55278A4
55278A4
18-7808
18-7808
40330
40330
508427
55278A2
55278A2
55278A5
55278A5
9-37750
