Fuel Pump/Cooler Kit – Fits Mercury/Mercruiser V6 & V8 Engines (Replaces 861156A04)
Fuel Pump/Cooler Kit – Fits Mercury/Mercruiser V6 & V8 Engines (Replaces 861156A04) is backordered and will ship as soon as it is back in stock.
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Worry-free returns
Worry-free returns
You may return most new, unopened items within 7 days of delivery for a full refund. We'll also pay the return shipping costs if the return is a result of our error (you received an incorrect or defective item, etc.).
You should expect to receive your refund within four weeks of giving your package to the return shipper, however, in many cases you will receive a refund more quickly. This time period includes the transit time for us to receive your return from the shipper (5 to 10 business days), the time it takes us to process your return once we receive it (3 to 5 business days), and the time it takes your bank to process our refund request (5 to 10 business days).
If you need to return an item, simply login to your account, view the order using the "Complete Orders" link under the My Account menu and click the Return Item(s) button. We'll notify you via e-mail of your refund once we've received and processed the returned item.
Delivery and Shipping
Delivery and Shipping
Free standard shipping on all orders under 1 KG
Fuel Pump/Cooler Kit – Fits Mercury/Mercruiser V6 & V8 Engines ...
Product Details
This Fuel Pump/Cooler Kit – Fits Mercury/Mercruiser V6 & V8 Engines (Replaces 861156A04) is designed for Mercury Marine/Mercruiser V6 and V8 engines equipped with Cool Fuel systems, specifically for serial numbers 0K999999 and below. It ensures reliable fuel delivery and cooling for optimal engine performance.
This kit serves as a direct replacement for Mercury part numbers 861156A04, 8M0125845, and Sierra 18-8863.
- Installation Method: Engine Mounted
- Key Technology: Features integrated Cool Fuel technology to prevent vapor lock.
- Housing: Durable copper and metal construction for corrosion resistance.
Part Number Matrix
Use this matrix to confirm equivalent references across OEM and aftermarket.
| Brand | Part Number | Superseded By |
|---|---|---|
| Mercury | 861156A04 | 8M0125845 |
| Sierra | 18-8863 |
Engine & Model Compatibility
Confirm your engine model/year in the table below.
This assembly is designed for specific Mercruiser sterndrive models. Verify your engine's serial number is 0K999999 or earlier and that it uses a Cool Fuel system.
| Brand | Model | Stroke | OEM Part No. | Notes |
|---|---|---|---|---|
| Mercruiser | GM V6 & V8 (305, 350, 377, 454 & 502 cid) | 4-Stroke | 861156A04/8M0125845 | With Cool Fuel system, S/N 0K999999 and below |
Technical Specs
- Product Type
- Fuel Pump and Cooler Kit
- Installation
- Engine Mounted
- Fuel Type
- Gasoline
- Housing Material
- Copper/Metal
- Housing Color
- Copper
- Dimensions
- 37 × 12 × 11 cm (14.6 × 4.7 × 4.3 inches)
- Weight
- 0.91 kg (32 oz)
- Warranty
- 1 year (Mercury Marine/Quicksilver)
- Other Technical Attributes
- Cool Fuel technology
What’s in the Box
- 1 × Fuel Pump/Cooler Kit (861156A04/8M0125845)
Installation Notes
- Disconnect the battery terminals to prevent electrical shorts.
- Relieve the fuel system pressure by following the manufacturer's specified procedure.
- Carefully disconnect the fuel lines and electrical connectors from the old fuel pump assembly.
- Remove the mounting bolts securing the old pump and cooler, then remove the assembly from the engine.
- Clean the mounting surface to ensure a proper seal with the new unit.
- Position the new fuel pump/cooler assembly and securely tighten the mounting bolts.
- Reconnect the fuel lines and electrical connectors to the new pump.
- Reconnect the battery terminals.
- Prime the fuel system according to your engine's service manual.
- Start the engine and carefully inspect for any fuel leaks around the connections. Do not operate if leaks are present.
Troubleshooting & FAQ
How do I confirm this fits my Mercruiser engine?
The most important factors are your engine's serial number and fuel system type. This kit is for engines with serial numbers 0K999999 and below that use the "Cool Fuel" system. Always verify using your engine's service manual or by checking the part number on your existing pump.
What are the signs of a failing fuel pump?
Common symptoms include the engine sputtering at high speeds, loss of power, difficulty starting, or stalling. These issues can indicate the pump is unable to supply a consistent fuel pressure.
What is a "Cool Fuel" system?
The Mercruiser Cool Fuel system uses a water-cooled chamber to lower the temperature of the fuel before it enters the engine. This helps prevent vapor lock, which can cause stalling and poor performance, especially in hot weather.
When should the fuel pump be replaced?
There is no fixed replacement interval. Fuel pumps are typically replaced when they fail or show signs of decreased performance. Regular inspection of fuel lines and filters is recommended as part of routine maintenance.
OEM vs. Aftermarket?
This listing is an aftermarket replacement (not OEM). Built to OEM-level specifications with comparable materials. Manufactured in an ISO 9002 facility, batch-inspected for consistency.
Shipping speed & cost
We ship worldwide quickly—typical transit 5–15 days. Standard shipping is free; expedited options appear at checkout where available.
Warranty & returns
Covered by a 1-year warranty against manufacturing defects under normal use. If issues arise, contact support with your order details. Returns are accepted within our standard window (unused & in original condition). See our policy page or reach out for instructions.
Safety & Important Info
- Verify images/specifications vs your original part. If anything differs—even if your model appears compatible—do not purchase.
- This is an aftermarket replacement, not an OEM component.
- Professional installation is recommended for safety and performance.
About Sea Sierra
- Pro-Grade Standards — We supply marine parts engineered to OEM-level tolerances and tested for real-world conditions.
- Fast Global Fulfillment — Free standard delivery to most regions in 5–15 days.
- Manufacturer-Direct Value — Fair pricing without compromising on materials or QC.
Payment & Security
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