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Mercury Outboard Parts
Shop OEM and aftermarket Mercury outboard parts for maintenance, repair, troubleshooting, and complete engine rebuild projects. Browse Mercury marine parts by system, including cooling, fuel delivery, electrical and ignition, internal engine components, lower unit parts, steering, trim, and routine service items.
Pro Marine USA carries Mercury outboard engine parts for a wide range of 2-stroke, FourStroke, EFI, Optimax, Pro XS, SeaPro, and Verado applications. Use your engine horsepower, model, serial number, or OEM part number whenever possible to confirm fitment before ordering.
Shop Mercury Outboard Parts by System
- Complete Powerheads
- Control Cables & Boxes
- Cooling System
- Cowlings & Components
- Electrical System
- Engine Oil
- Engine Rebuild Kits
- Fuel & Carburetion System
- Intake System
- Internal Engine Components
- Lower Unit Components
- Oiling System
- Paints
- Service & Oil Change Kits
- Service Manuals
- Steering Systems
- Throttle Components
- Transom & Midsection
- Trim System
- Wizard Performance Parts
Find the Correct Mercury Outboard Part
Mercury outboard parts can vary by horsepower, engine family, model year, and serial number range. If you are unsure which component fits your engine, use the OEM parts lookup to locate the original Mercury part number from an engine diagram.
Once you have the OEM part number, search Pro Marine to find available genuine Mercury and aftermarket replacement options.
Use Our OEM Parts Lookup »Common Mercury Outboard Engine Families
Pro Marine supports many Mercury outboard applications across a wide horsepower range. Always confirm the engine serial number and model information before ordering parts.
- Portable and Midrange: Mercury 2.5HP through 60HP 2-stroke and FourStroke applications
- FourStroke and EFI: common 75HP through 300HP Mercury EFI and FourStroke platforms
- Pro XS: performance-oriented Mercury Pro XS outboards across multiple engine families
- Optimax: direct-injected 2-stroke Mercury Optimax engines, commonly 75HP through 250HP
- Verado: supercharged and naturally aspirated Mercury Verado applications from 135HP through current high-horsepower platforms
- SeaPro: commercial-duty Mercury SeaPro outboards used in professional and high-hour applications
Common Mercury Outboard Repair Areas
- Overheating: inspect the water pump, impeller, thermostat, poppet valve, cooling passages, and related cooling components.
- Hard starting or rough running: inspect fuel pumps, filters, injectors or carburetors, spark plugs, coils, sensors, and intake components.
- No spark or intermittent ignition: check ignition coils, stators, switch boxes, trigger assemblies, sensors, grounds, and wiring.
- Low compression or power loss: inspect pistons, rings, cylinders, bearings, gaskets, reeds, and internal engine components.
- Lower unit noise or water intrusion: inspect seals, bearings, gears, shafts, bearing carriers, and gear lube condition.
- Trim or steering problems: inspect trim motors, pumps, hydraulic components, steering cylinders, hoses, and related rigging parts.
Why Buy Mercury Outboard Parts from Pro Marine USA?
- OEM Mercury and aftermarket replacement options for many common applications.
- Parts for maintenance, repair, engine rebuilding, lower units, electrical systems, fuel systems, steering, trim, and rigging.
- OEM diagram and part-number lookup tools to help identify the correct part before ordering.
- Dealer pricing available for qualified marine repair businesses and dealers.
- Large inventory of Mercury service parts and hard-to-find marine engine components.
- Fast weekday shipping on qualifying in-stock orders.
Frequently Asked Questions
How do I find the correct Mercury outboard part?
Use the engine horsepower, model, serial number, and year whenever available. Mercury frequently uses serial-number ranges to identify engine families, so the serial number is often the most reliable way to confirm fitment.
Can I search Mercury parts by OEM part number?
Yes. Enter the Mercury OEM part number into the Pro Marine site search to locate available OEM and aftermarket replacement options. If you do not know the part number, use the OEM parts lookup first.
Do Mercury outboard parts vary by serial number?
Yes. Many Mercury components change by serial-number range even within the same horsepower or model family. Always compare the serial range listed for the part with your engine before ordering.
Do you carry parts for Mercury Optimax and Verado engines?
Yes. Pro Marine carries parts for many Mercury Optimax, Verado, Pro XS, EFI, FourStroke, and SeaPro applications, including maintenance, fuel, electrical, cooling, internal engine, lower unit, steering, and rigging components.
Do you carry both OEM and aftermarket Mercury parts?
Yes. Pro Marine offers genuine Mercury parts along with aftermarket replacement parts for many common Mercury outboard maintenance, repair, and rebuild applications.
What Mercury outboard parts are commonly replaced during routine maintenance?
Common maintenance items include engine oil, oil filters, fuel filters, spark plugs, water pump kits, impellers, thermostats, gear lube, drain plug seals, anodes, and manufacturer-specific service kit components.
Fitment Tip: Mercury outboard parts often vary by serial-number range. Confirm your engine serial number and OEM part number whenever possible before ordering.
21150
37432
55421A1
76062A1
18-7804
23014A1
23014A1
40310
40310
508425
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