Drive Belt for MerCruiser, Volvo Penta, OMC 17HP-350HP Models (57-74271Q)

Drive Belt – Fits MerCruiser, Volvo Penta, OMC 17HP-350HP (Replaces 57-74271Q, 966903)

This high-quality aftermarket drive belt is engineered for reliable performance in a wide range of MerCruiser, Volvo Penta, and OMC 4-stroke marine engines, from 17HP to 350HP. It serves as a direct replacement component, ensuring proper fit and function for various alternator, power steering, and sea water pump applications.

This belt directly replaces MerCruiser part numbers 57-68038, 57-74271Q, 57-74271T, 57-77274, 68038, 74271, 74271T, 77274A1; Volvo Penta part numbers 960281, 966903; and OMC part numbers 0509306, 0509308.

• Designed for a direct, hassle-free replacement of your original OEM belt.
• Constructed from durable materials to withstand the harsh marine environment.
• Backed by a 1-year warranty against manufacturing defects for peace of mind.

Part Number Cross-Reference

Use this table to confirm equivalent part numbers across OEM and aftermarket brands.

Compatible Engine Models

Confirm your engine model/year in the table below. For MerCruiser owners, here’s a guide to help you identify your engine’s serial/model: Mercury Serial Number Guide. You can also review exploded diagrams to verify part numbers: Mercury Parts Diagrams & Catalog.

Technical Specifications

Package Contents

1 x Drive Belt (Replaces 57-74271Q / 966903)

Installation Guide

1. Safety First: Ensure the engine is completely cool and turned off. Disconnect the boat's battery.
2. Locate the Belt: Identify the existing drive belt and its path around the engine pulleys. Taking a photo can be helpful.
3. Release Tension: Use the appropriate tool to loosen the idler or tensioner pulley, releasing tension from the belt.
4. Remove Old Belt: Carefully slide the old belt off all pulleys.
5. Inspect Pulleys: Before installing the new belt, spin each pulley by hand. Check for wobble, roughness, or signs of wear.
6. Route New Belt: Following your photo or the engine diagram, route the new belt around the pulleys, ensuring it sits correctly in the grooves.
7. Apply Tension: Carefully re-engage the tensioner to apply the correct amount of tension to the new belt. Do not overtighten.
8. Final Check: Reconnect the battery. Briefly start the engine to ensure the belt tracks properly and operates smoothly without noise.

Troubleshooting & FAQ

How can I be sure this belt fits my MerCruiser engine?
The most reliable method is to match your engine's model and serial number to the ranges listed in our compatibility table. The serial number is critical for confirming the correct fitment for MerCruiser engines.

My engine isn't on the list, but my old belt's part number matches. Will it fit?
Yes. If your current belt has one of the part numbers listed in our cross-reference section (e.g., 57-74271Q or 966903), this product is designed as a direct replacement.

What are the signs that my drive belt needs to be replaced?
Common indicators of a failing belt include loud squealing or chirping noises from the engine, visible cracks or fraying on the belt's surface, and inconsistent performance of belt-driven components like the alternator or water pump.

How often should I inspect my drive belt?
Regular visual inspection is recommended during routine engine maintenance. Look for glazing, cracks, or contamination from oil. We suggest replacing it based on visible wear or according to your engine manufacturer's recommended service intervals.

OEM vs. Aftermarket?
This listing is an aftermarket replacement part (not an OEM component). We build to OEM specifications using comparable-grade materials. Production is done in an ISO9002-certified facility, and each batch is inspected for consistent performance.

How fast do you ship and how much does it cost?
We offer fast global shipping—typically 5–15 days worldwide—and standard shipping is free. Expedited options are available at checkout depending on your location.

What is your warranty and return policy?
This product includes a 1-year warranty against manufacturing defects under normal use. If something goes wrong, contact our support team with your order details. Returns are accepted within our standard return window (unused & in original condition); please see our policy page or reach out for instructions.

Important Notes

• Verify that the product images and specifications match your original part. If discrepancies exist—even if your model is listed—do not proceed with the purchase.
• This product is an aftermarket replacement part and is not an OEM component.
• Professional installation is recommended to ensure safety and optimal performance.

Why Choose JLM MARINE?

• Quality Assured: As a trusted manufacturer for over 20 years, we supply top marine brands globally.
• Fast Global Shipping: Free delivery worldwide in 5–15 days.
• Direct from Manufacturer: Competitive pricing without compromising quality.