Serpentine Belt – Fits MerCruiser 4.3L-6.2L (Replaces 57-865615Q04, 57-8638764, 57-862086A1, 57-8620861)
Serpentine Belt – Fits MerCruiser 4.3L-6.2L (Replaces 57-865615Q04, 57-8638764, 57-862086A1, 57-8620861) 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
Serpentine Belt – Fits MerCruiser 4.3L-6.2L (Replaces 57-865615Q04,...
Product Details
This high-quality Serpentine Belt is designed for a precise fit on MerCruiser V6 4.3L and V8 5.0L, 5.7L, and 6.2L sterndrive engines from 2001 and newer (serial number 0M320025 and above) that use a standard cooling system. It serves as a reliable, direct replacement for the original equipment manufacturer (OEM) belt to maintain proper engine accessory function.
This belt directly replaces Mercury/MerCruiser part numbers 57-865615Q04, 865615004, 57-8638764, 57-862086A1, 57-8620861, and Sierra 18-15101.
- Engineered as a direct replacement for simple installation with common tools.
- Specifically for MerCruiser engines with standard (raw water) cooling systems.
- Constructed from durable, fiber-reinforced rubber for longevity and reliable performance.
Part Number Matrix
Use this matrix to confirm equivalent references across OEM and aftermarket.
| Brand | Part Number |
|---|---|
| Mercury / MerCruiser | 57-865615Q04 |
| Mercury / MerCruiser | 865615004 |
| Mercury / MerCruiser | 57-8638764 |
| Mercury / MerCruiser | 57-862086A1 |
| Mercury / MerCruiser | 57-8620861 |
| Sierra | 18-15101 |
Engine & Model Compatibility
Confirm your engine model/year in the table below.
For MerCruiser Engines: This belt is compatible with the models listed below, specifically for sterndrive engines with standard cooling systems, starting from serial number 0M320025 (model year 2001 and newer).
| Brand | Model | Rated HP | Stroke | Years | OEM Part No. | Notes |
|---|---|---|---|---|---|---|
| MerCruiser | 4.3L 262 CID V-6 | 190–220 | 4-Stroke | 2001+ (0M320025-1A063239) | 57-865615Q04 | Standard cooling only |
| MerCruiser | 4.3L 262 CID V-6 | 190–220 | 4-Stroke | 1A063240 & Up | 57-865615Q04 | Standard cooling only |
| MerCruiser | 4.3L MPI 262 CID V-6 | 220 | 4-Stroke | 2001+ (0M615000-0W309999) | 57-865615Q04 | Standard cooling only |
| MerCruiser | 4.3L MPI 262 CID V-6 | 220 | 4-Stroke | 0W310000-0W649999 | 57-865615Q04 | Standard cooling only |
| MerCruiser | 4.3L MPI 262 CID V-6 | 220 | 4-Stroke | 0W650000-0W658582 | 57-865615Q04 | Standard cooling only |
| MerCruiser | 4.3L MPI 262 CID V-6 | 220 | 4-Stroke | 0W658583-1A063239 | 57-865615Q04 | Standard cooling only |
| MerCruiser | 4.3L MPI 262 CID V-6 | 220 | 4-Stroke | 1A063240 & Up | 57-865615Q04 | Standard cooling only |
| MerCruiser | 5.0L 305 CID V-8 | 260 | 4-Stroke | 2001+ (0M320025-1A623184) | 57-865615Q04 | Standard cooling only |
| MerCruiser | 5.0L 305 CID V-8 | 260 | 4-Stroke | 1A623185 & Up | 57-865615Q04 | Standard cooling only |
| MerCruiser | 5.0L MPI 305 CID V-8 Alpha | 260 | 4-Stroke | 2001+ (1A300000-1A611927) | 57-865615Q04 | Standard cooling only |
| MerCruiser | 5.0L MPI 305 CID V-8 Alpha | 260 | 4-Stroke | 1A611928-1A623184 | 57-865615Q04 | Standard cooling only |
| MerCruiser | 5.0L MPI 305 CID V-8 Alpha | 260 | 4-Stroke | 1A623185 & Up | 57-865615Q04 | Standard cooling only |
| MerCruiser | 5.7L 350 CID V-8 | 300 | 4-Stroke | 2001+ (0M320025-1A623184) | 57-865615Q04 | Standard cooling only |
| MerCruiser | 5.7L 350 CID V-8 | 300 | 4-Stroke | 1A623185 & Up | 57-865615Q04 | Standard cooling only |
| MerCruiser | 5.7L MAG MPI 350 CID Alpha | 300–315 | 4-Stroke | 2001+ (1A300000-1A611927) | 57-865615Q04 | Standard cooling only |
| MerCruiser | 5.7L MAG MPI 350 CID Alpha | 300–315 | 4-Stroke | 1A611928-1A623184 | 57-865615Q04 | Standard cooling only |
| MerCruiser | 5.7L MAG MPI 350 CID Alpha | 300–315 | 4-Stroke | 1A623185 & Up | 57-865615Q04 | Standard cooling only |
| MerCruiser | 6.2L 377 CID MAG MPI | 320–377 | 4-Stroke | 2001+ (1A611928-1A623184) | 57-865615Q04 | Standard cooling only |
| MerCruiser | 6.2L 377 CID MAG MPI | 320–377 | 4-Stroke | 1A623185 & Up | 57-865615Q04 | Standard cooling only |
Technical Specs
- Product Type
- Serpentine Belt
- Belt Length
- 1,941 mm (76.5 inches)
- Belt Width
- 20.6 mm (13/16 inches)
- Material
- High-grade rubber with fiber reinforcement
- Application
- Standard cooling, Alpha drive engines
- Replaces OEM
- Yes - Same as originally installed by MerCruiser
- Year Range
- 2001 and newer
- Serial Number Range
- 0M320025 and above
- Installation
- Direct replacement with common tools
- Warranty
- 1 year against manufacturing defects
What’s in the Box
- 1 x Serpentine Belt (Replaces 57-865615Q04)
Installation Notes
- Safety First: Before starting, disconnect the boat's battery to prevent accidental engine start-up.
- Locate the Belt: Identify the serpentine belt routing around the engine's pulleys. Taking a photo can be helpful for referencing later.
- Release Tension: Use a socket or breaker bar on the automatic tensioner pulley to release the belt's tension.
- Remove Old Belt: Carefully slip the old belt off the pulleys.
- Inspect Pulleys: Before installing the new belt, spin each pulley by hand to ensure they rotate smoothly and are free of debris.
- Route New Belt: Following your photo or the engine diagram, route the new belt around all pulleys except for the tensioner.
- Apply Tension: While holding tension off the tensioner, slide the belt over the final pulley. Slowly release the tensioner to tighten the belt.
- Check Alignment: Ensure the belt is correctly seated in the grooves of every pulley.
- Final Check: Reconnect the battery and briefly start the engine to confirm the belt runs smoothly and quietly.
Troubleshooting & FAQ
How do I know if this belt is the correct one for my engine?
The most reliable way to confirm fitment is by checking your engine's serial number. This belt fits MerCruiser models with serial numbers 0M320025 and above. Also, ensure your engine uses a standard (raw water) cooling system, as this belt is not for closed cooling systems.
What are the signs of a worn or failing serpentine belt?
Common signs include visible cracks, fraying, or glazing on the belt's surface. You may also hear a persistent squealing or chirping sound from the engine bay, especially during start-up or when the engine is under load.
Can I use this serpentine belt on an engine with a closed cooling system?
No. This belt is specifically designed for engines equipped with standard (raw water) cooling systems. The belt routing and length are different for closed cooling systems, so this part will not fit correctly.
How often should a serpentine belt be replaced?
There is no fixed interval; replacement should be based on condition. It is best practice to inspect the belt during routine maintenance for signs of wear such as cracking, glazing, or fraying. Many owners replace them proactively every few hundred hours or every 3-5 years to prevent unexpected failure.
Is this an official Mercury MerCruiser OEM part?
This listing is an aftermarket replacement, not an OEM part. It has been manufactured to meet or exceed original equipment specifications using comparable high-quality materials in an ISO 9002 certified facility and is batch-inspected for quality assurance.
How fast is shipping?
We ship worldwide, with most orders arriving in 5 to 15 days via standard delivery. Expedited shipping options and exact costs are available at checkout.
What is the warranty and return policy?
This product is covered by a 1-year warranty against manufacturing defects under normal use conditions. If you encounter a problem, please contact our support team. Returns for unused items in their original condition are accepted within our standard return window.
Safety & Important Info
- Verify images and specifications against your original part before purchase. If anything differs—even if your model is listed as compatible—do not order.
- This is an aftermarket replacement component, not an OEM part.
- Professional installation is highly recommended for safety and optimal performance.
About Sea Sierra
- Pro-Grade Standards — We supply marine parts engineered to OEM-level tolerances and rigorously tested for real-world conditions.
- Fast Global Fulfillment — We offer free standard delivery to most regions, with typical transit times of 5–15 days.
- Manufacturer-Direct Value — By working directly with manufacturers, we provide fair pricing without compromising on materials or quality control.
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