S2K Commerce - Products Dropdown
Actions
S2K Commerce - Order Entry
Actions
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.
39210
508659
73645A32
73645A76
73645A87
850026A1
850026A3
850026T1
850026T3
850051A1
39330
55306A72
55306A73
55306A74
55306A75
78028A78
18-4352
39180
508688
60308A72
64859A73
64859A74
69524A75
73440A76
76589A77
76589A78
76589A79
88449A32
88449A80
9-64208
822844
822844T04
822844T05
822844004
8228441
8228442
8228443
18-0904
508681
60317
9002A4
9002A6
Genuine Mercury Marine OEM Engine Components
Genuine Mercury 8M0118179 Cylinder Head Gasket for 35-60 HP 4-Stroke Outboards
The Genuine Mercury 8M0118179 Cylinder Head Gasket is an original equipment manufacturer (OEM) replacement for select Mercury 35, 40, 50, and 60 HP 4-cylinder 4-stroke outboard engines. Compatible applications include specified carbureted and EFI engines, along with certain EFI Jet, SeaPro, APX, Formula 60, and 60R EFI Racing configurations.
This factory replacement gasket provides the sealing interface between the cylinder head and engine block. It helps maintain combustion chamber compression while separating the engine's cooling water and lubrication passages.
Mercury OEM part number 8M0118179 is listed as the replacement for earlier Mercury cylinder head gasket numbers 857081 and 8M0045278.
This genuine Mercury gasket is intended for compatible cylinder head repairs, gasket replacement, and powerhead service where a factory OEM replacement is preferred.
Pro Marine Aftermarket Alternative Available: We also stock Pro Marine 7081 Cylinder Head Gasket for the same listed applications.
Product Information
- Pro Marine Item Number: 857081
- Manufacturer: Mercury Marine
- Brand: Genuine Mercury OEM
- Current OEM Part Number: 8M0118179
- Previous OEM Numbers: 857081, 8M0045278
- Product Type: Cylinder Head Gasket
- Engine Manufacturer: Mercury Marine
- Engine Type: 4-Stroke Outboard
- Engine Configuration: Inline 4 Cylinder
- Primary Horsepower Applications: 40, 50, and 60 HP
- Additional Application: 35 HP EFI Jet
- Fuel Systems: Carbureted and EFI, depending on model
- Additional Engine Families: SeaPro, APX, Formula 60, 60R EFI Racing
- Application: Cylinder Head to Engine Block
- Condition: New
- Aftermarket Alternative: Pro Marine 7081
OEM and Cross Reference Numbers
Genuine Mercury 8M0118179 is the listed factory replacement for the following Mercury cylinder head gasket numbers.
| Manufacturer | Part Number | Description |
|---|---|---|
| Mercury Marine | 8M0118179 | Current Genuine Mercury OEM Replacement |
| Mercury Marine | 8M0045278 | Previous OEM Part Number |
| Mercury Marine | 857081 | Earlier OEM Part Number |
Mercury OEM Replacement Information
Mercury part numbers 857081 and 8M0045278 are listed under the current replacement number 8M0118179.
If your original engine parts diagram references an earlier gasket number, confirm the replacement against your complete Mercury engine serial number before ordering.
What This Part Is Used For
The Mercury cylinder head gasket seals the joint between the cylinder head and engine block on compatible 4-cylinder 4-stroke outboard engines.
This gasket helps maintain combustion pressure while preventing cooling water and engine oil from leaking between internal engine passages.
Genuine Mercury 8M0118179 is used during cylinder head removal, gasket replacement, and compatible engine repair procedures.
Common Repair Applications
- Mercury 40 HP 4-stroke cylinder head gasket replacement
- Mercury 50 HP carbureted and EFI cylinder head service
- Mercury 60 HP EFI cylinder head repairs
- Compatible Mercury EFI Jet outboard repairs
- Compatible Mercury SeaPro engine repairs
- Mercury 60 HP APX engine service
- Mercury Formula 60 engine repairs
- Mercury 60R EFI Racing cylinder head service
- Repairs involving compression or cooling water leakage
- Compatible Mercury 4-cylinder powerhead rebuilding
Important Fitment Note
Genuine Mercury 8M0118179 is listed for select Mercury 35-60 HP 4-cylinder 4-stroke engines. Not every Mercury engine within this horsepower range uses the same cylinder head gasket.
Mercury produced several engine configurations within these horsepower ranges, including different cylinder counts, carbureted and EFI fuel systems, and specialized Jet, SeaPro, APX, and Racing models.
The 35 HP application shown in the supplied Mercury catalog is specifically a 35 HP EFI Jet 4-cylinder. This does not establish fitment for every Mercury 35 HP outboard.
Verify your complete Mercury engine serial number and the required OEM cylinder head gasket number before ordering.
Compatible Mercury Outboard Applications
The following engine applications are organized from Mercury parts catalog information. Compatibility is determined by the engine configuration and serial number.
| Mercury Engine Family | Horsepower | Configuration |
|---|---|---|
| EFI Jet | 35 HP | 4 Cylinder |
| FourStroke | 40 HP | 4 Cylinder Carbureted / EFI |
| EFI Jet / SeaPro | 40 HP | 4 Cylinder EFI |
| FourStroke | 50 HP | 4 Cylinder Carbureted / EFI |
| FourStroke / SeaPro | 60 HP | 4 Cylinder EFI |
| APX | 60 HP | 1.0L EFI L4 |
| 60R EFI Racing | 60 HP | Racing Outboard |
| Formula 60 | 60 HP | Formula Racing Application |
EFI Jet, SeaPro, APX and Racing Serial Number Applications
| Engine Model | Serial Number Range | Mercury Catalog Reference |
|---|---|---|
| 35 HP EFI Jet 4 Cyl | 1C453840 and later | 90-8M0118807 |
| 40 HP EFI Jet 4 Cyl | 1C453840 and later | 90-8M0118807 |
| 40 HP EFI SeaPro 4 Cyl | 1C453840 and later | 90-8M0118807 |
| 60 HP EFI SeaPro 4 Cyl | 1C453840 and later | 90-8M0118807 |
| 60 HP 1.0L EFI L4 APX | 1C782688 and later | 90-8M0236731 |
| 60R HP EFI Racing | 1C615064 and later | 90-8M0169885 |
| Formula 60 | 1C104574 through 1C782687 | 90-8M0083070 |
Mercury 40-60 HP Carbureted 4-Cylinder Applications
| Horsepower | Serial Number Range | Market |
|---|---|---|
| 40 / 50 / 60 HP Carb | 0P094500 through 0P206999 | Belgium |
| 40 / 50 / 60 HP Carb | 0T178500 through 0T598999 | USA |
Mercury 40-60 HP EFI 4-Cylinder Serial Number Fitment
The following serial number ranges are listed for Mercury 40, 50, and 60 HP EFI 4-cylinder engines.
| Horsepower | Serial Number Range | Market | Catalog Reference |
|---|---|---|---|
| 40 / 50 / 60 HP EFI | 0P153500 through 0P400999 | Belgium | 90-88387502 |
| 40 / 50 / 60 HP EFI | 0T409000 through 1B355222 | USA | 90-88387502 |
| 40 / 50 / 60 HP EFI | 1C000001 through 1C050251 | USA | 90-883875003 |
| 40 / 50 / 60 HP EFI | 0P401000 through 0P515896 | Belgium | 90-883875003 |
| 40 / 50 / 60 HP EFI | 1C050252 through 1C453839 | USA | 90-883875008 |
| 40 / 50 / 60 HP EFI | 0P515897 through 0P580772 | Belgium | 90-883875008 |
Later-Production Mercury EFI Applications
| Engine Model | Serial Number | Catalog Reference |
|---|---|---|
| 40 HP EFI 4 Cylinder | 1C453840 and later | 90-8M0118807 |
| 50 HP EFI 4 Cylinder | 1C453840 and later | 90-8M0118807 |
| 60 HP EFI 4 Cylinder | 1C453840 and later | 90-8M0118807 |
Understanding Mercury Catalog Fitment
Mercury parts catalogs may list this gasket in both cylinder head diagrams and powerhead gasket set component diagrams. These references identify applicable engine configurations and do not mean that this individual gasket includes the complete powerhead gasket set.
Use the engine's complete serial number and the appropriate Mercury parts diagram to confirm the required cylinder head gasket.
Pro Marine Aftermarket Cylinder Head Gasket Available
Looking for an aftermarket alternative to the Genuine Mercury factory gasket? Pro Marine USA also stocks the Pro Marine 7081 Cylinder Head Gasket for the same listed Mercury applications.
Pro Marine 7081 - Aftermarket Cylinder Head Gasket
Pro Marine aftermarket replacement cylinder head gasket for compatible Mercury 35-60 HP 4-cylinder 4-stroke outboard engines.
Pro Marine Part: 7081
OEM Cross References: 857081, 8M0045278, 8M0118179
Brand: Pro Marine Aftermarket
Common Symptoms of a Failed Cylinder Head Gasket
A failed cylinder head gasket can allow combustion gases, engine oil, or cooling water to leak between internal engine passages.
Possible symptoms include:
- Loss of compression in one or more cylinders
- Engine overheating
- Cooling water entering the combustion chamber
- Water contamination in engine oil
- Rough idle or engine misfires
- Reduced engine performance
- Difficulty starting
- Combustion gases entering the cooling system
- Visible damage to the original cylinder head gasket
These symptoms may have multiple causes. Perform appropriate engine diagnostic testing before determining that the cylinder head gasket requires replacement.
Installation and Service Tips
Replacing a Mercury 4-cylinder cylinder head gasket requires cylinder head removal and inspection of the engine's sealing surfaces.
Follow the Mercury service manual for your exact engine serial number and configuration.
Recommended Installation Practices
- Confirm the complete Mercury engine serial number.
- Verify that the engine uses OEM gasket 8M0118179 or an applicable earlier number.
- Allow the engine to cool before beginning disassembly.
- Follow Mercury's specified cylinder head removal procedure.
- Inspect the cylinder head and engine block sealing surfaces.
- Check for warpage, cracks, corrosion, and other damage.
- Remove old gasket material without damaging sealing surfaces.
- Keep debris out of cylinders, oil passages, and cooling passages.
- Install the new gasket in the correct orientation.
- Follow the manufacturer's specified tightening sequence.
- Use the correct cylinder head fastener torque procedure.
- Replace additional fasteners or seals when required by the service manual.
- Inspect the cooling system for conditions that caused the original gasket failure.
- Check engine operation and cooling performance after reassembly.
Important Cylinder Head Installation Warning
Correct cylinder head gasket installation requires proper surface preparation, cylinder head inspection, and the specified Mercury tightening procedure.
Do not install a new cylinder head gasket over warped, cracked, or improperly prepared sealing surfaces. Incorrect installation can result in compression loss, cooling water leakage, overheating, and engine damage.
Key Features and Benefits
- Genuine Mercury OEM: Factory replacement cylinder head gasket for compatible Mercury 4-stroke outboards.
- Mercury 4-Cylinder Compatibility: Listed for select 35-60 HP engine configurations.
- Carbureted and EFI Applications: Includes specified Mercury 40, 50, and 60 HP 4-cylinder engine families.
- Specialized Mercury Models: Catalog references include EFI Jet, SeaPro, APX, Formula 60, and 60R EFI Racing.
- OEM Part Number 8M0118179: Listed replacement for earlier Mercury 857081 and 8M0045278 numbers.
- Factory Replacement Component: Intended for compatible cylinder head service and repairs.
- Aftermarket Alternative Available: Pro Marine 7081 is stocked separately.
- Dealer Pricing Available: Qualified marine businesses can apply for wholesale pricing.
Frequently Asked Questions
Is Mercury 8M0118179 a Genuine OEM cylinder head gasket?
Yes. Mercury 8M0118179 is a Genuine Mercury Marine OEM cylinder head gasket for compatible 4-cylinder 4-stroke outboards.
Does Mercury 8M0118179 replace 857081?
Yes. Mercury 8M0118179 is the listed replacement for earlier OEM number 857081.
Does Mercury 8M0118179 replace 8M0045278?
Yes. Mercury 8M0045278 is also listed as a previous OEM number for this cylinder head gasket.
Does this head gasket fit Mercury 40 HP 4-stroke engines?
Yes. This gasket is listed for select Mercury 40 HP carbureted and EFI 4-cylinder 4-stroke engines. Confirm the serial number before ordering.
Does this gasket fit Mercury 50 HP EFI outboards?
Yes. Compatible applications include specified Mercury 50 HP EFI 4-cylinder outboards.
Does this gasket fit Mercury 60 HP 4-stroke engines?
Yes. It is listed for select Mercury 60 HP EFI 4-cylinder engines, including certain SeaPro and specialized racing applications.
Does this gasket fit Mercury 35 HP outboards?
The supplied Mercury catalog lists a 35 HP EFI Jet 4-cylinder application. This does not mean the gasket fits every Mercury 35 HP engine.
Is this gasket used on Mercury Formula 60 engines?
Formula 60 appears in the supplied Mercury catalog for serial numbers 1C104574 through 1C782687. Confirm the required gasket using the appropriate parts diagram.
Does this gasket fit Mercury 60R EFI Racing engines?
The supplied catalog includes Mercury 60R EFI Racing models beginning at serial 1C615064. Verify the engine configuration before ordering.
Is there a Pro Marine aftermarket version available?
Yes. Pro Marine USA also offers Pro Marine 7081 as an aftermarket replacement for the same listed applications.
How do I confirm the correct head gasket for my Mercury outboard?
Locate your complete Mercury engine serial number and compare it with the applicable Mercury parts diagram. Confirm that the diagram identifies 8M0118179 or one of its listed earlier OEM numbers.
Dealer Discounts & Store Policies
Wholesale Marine Parts Pricing
Pro Marine USA supplies Genuine Mercury OEM and aftermarket marine engine parts, cylinder head gaskets, internal engine components, rebuild parts, and maintenance products to marine repair shops, dealerships, technicians, and retail customers.
Qualified marine businesses can apply for a Pro Marine dealer account to access wholesale pricing on eligible marine parts.
Shipping Information
- Free shipping on orders over $100 within the continental United States.
- In-stock orders received before 5:30 PM EST ship the same business day, Monday-Friday.
- Shipping options available through UPS, USPS, and FedEx.
- Typical delivery time is 1-5 business days.
30-Day Return Policy
- Eligible returns are accepted within 30 days.
- Parts must be new, unused, and in original packaging.
- Installed parts are not returnable.
- Return authorization is required before returning merchandise.
Need Help Confirming Mercury Fitment?
If you are unsure whether Genuine Mercury 8M0118179 is the correct cylinder head gasket for your Mercury outboard, contact Pro Marine USA with your engine horsepower and complete serial number.
Contact Pro Marine USA or call 941-721-3000.
Searchable Part Numbers
857081, 8M0118179, 8M0045278, 7081
Searchable Terms
Genuine Mercury 857081, Genuine Mercury 8M0118179, Mercury 8M0045278, Mercury OEM cylinder head gasket, Mercury factory head gasket, Mercury 4 stroke head gasket, Mercury 4 cylinder head gasket, Mercury 35 HP EFI Jet head gasket, Mercury 40 HP head gasket, Mercury 50 HP head gasket, Mercury 60 HP head gasket, Mercury 40 EFI cylinder head gasket, Mercury 50 EFI cylinder head gasket, Mercury 60 EFI cylinder head gasket, Mercury 40 SeaPro head gasket, Mercury 60 SeaPro head gasket, Mercury 40 HP EFI Jet gasket, Mercury 60 HP APX head gasket, Mercury 60R EFI Racing head gasket, Mercury Formula 60 head gasket, Mercury 40 50 60 HP head gasket, Mercury outboard cylinder head gasket, Mercury FourStroke head gasket, Mercury 4 cylinder powerhead gasket, Mercury outboard engine rebuild, Mercury cylinder head repair, Mercury head gasket replacement, Mercury blown head gasket, Mercury low compression, Mercury cooling water intrusion, Mercury OEM engine parts, original Mercury head gasket, factory Mercury replacement gasket, Pro Marine 857081, Pro Marine 7081 aftermarket alternative
8M0118179
857081
821945T65
821945T74
881908T
88721A1
