Marine Exhaust Bellow Kit 4PCS - 2x Upper 3852696 + 2x Lower 3863450 for Volvo Penta OMC Cobra 4.3L 5.0L 5.7L 7.4L 8.1L 8.2L V6 V8 Engines 1986-2025

Marine Exhaust Bellow Kit - 4-Piece Set

This is anexhaust bellow kit designed for Volvo Penta and OMC sterndrive engines. It provides a direct replacement for upper and lower exhaust bellows, facilitating a comprehensive exhaust system service. This kit is manufactured from 4-layer reinforced EPDM rubber for heat and environmental resistance, and includes marine-grade 316 stainless steel clamps for secure, corrosion-resistant connections.

The bellows are designed to absorb engine vibration, reduce noise, and accommodate thermal expansion to prevent stress on the exhaust system. This kit is a direct replacement for Volvo Penta parts 3852696 and 3863450, and Sierra parts 18-2779 and 18-2780-1.

• Fits a wide range of Volvo Penta and OMC Cobra engines from 1986 to 2025.
• Engineered to meet SAE J2006 R1 and ABYC standards.
• Includes all necessary clamps and mounting hardware for installation.

Part Number Cross-Reference

Use this table to confirm equivalent part numbers across OEM andbrands.

Compatible Engine Models

Confirm your engine model/year in the table below.

Technical Specifications

Package Contents

This is a complete 4-piece kit containing: 2x Upper Bellows (3852696) and 2x Lower Bellows (3863450).

• 2x Upper Exhaust Bellows (Replaces 3852696)
• 2x Lower Exhaust Bellows (Replaces 3863450)
• 8x 316 Stainless Steel Clamps
• Complete Mounting Hardware Kit

Installation Guide

1. Thoroughly clean all connection surfaces on the transom and drive before starting.
2. Check the alignment of the connection points, ensuring it is between 88 and 90 degrees.
3. Apply a suitable marine-grade sealant to the sealing surfaces for a leak-proof fit.
4. Fit the bellows into position. They are a direct OEM replacement and should not require modification.
5. Secure the upper bellow clamps, tightening to a torque specification of 25-30 Nm.
6. Secure the lower bellow clamps, tightening to a torque specification of 20-25 Nm.
7. After installation, perform a pressure test to check for any leaks before operating the vessel in water.

Troubleshooting & FAQ

How do I confirm this kit fits my specific engine?

Please review the "Compatible Engine Models" table on this page. Match your engine's brand, model series, and year to confirm fitment. You can also compare your existing part numbers to those in the "Part Number Cross-Reference" table.

What are the signs that my exhaust bellows need replacement?

Common signs of failure include visible cracks, hardening or swelling of the rubber, brittleness, or water leaking into the bilge area from the transom assembly. A noticeable increase in exhaust noise inside the boat can also indicate a leak.

How often should I inspect or replace the bellows?

A visual inspection is recommended every 50 hours or monthly. A detailed check should be performed seasonally or every 100 hours. The typical replacement interval is every 2000-3000 operating hours or 5-7 years, whichever comes first.

OEM vs. Aftermarket?

This listing is anreplacement 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 anreplacement 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.