Exhaust Manifold Bellow 70981A3 – Fits MerCruiser 120/140/3.0L 4-Cylinder & Various V6/V8 Models

Exhaust Manifold Bellow 70981A3 – Fits MerCruiser 120/140/3.0L 4-Cylinder & Various V6/V8 Models

This exhaust bellow is designed to connect the upper exhaust manifold to the elbow in various MerCruiser sterndrive engines. It is a direct-fit replacement for models utilizing a wet joint exhaust system, including a wide range of 4-cylinder, V6, and V8 engines manufactured between 1982 and 2002.

This part directly replaces MerCruiser 70981A3, Sierra 18-2762, GLM 89070, Mallory 9-72808, and Quicksilver 70981A3.

• Material: High-durability CR (Chloroprene) rubber for longevity.
• Connection: Fits 3-inch center mounted risers connecting to 4-inch elbows.
• Application: Designed for 2-piece exhaust elbows in wet joint systems.

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 Mercury 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 Exhaust Bellow/Boot (70981A3)

Installation Guide

1. Safety First: Ensure the engine is completely cool and disconnect the battery terminals.
2. Locate the Bellow: Access the exhaust system where the manifold riser connects to the exhaust elbow.
3. Remove Old Clamps: Loosen and remove the hose clamps securing the old exhaust bellow at both ends.
4. Remove Old Bellow: Carefully pry or cut the old bellow off the riser and elbow. Be prepared for some water to drain out.
5. Clean Surfaces: Thoroughly clean the connection surfaces on both the riser and the elbow to ensure a proper seal. Remove any old sealant or rubber residue.
6. Install New Bellow: Slide the new clamps over the bellow, then fit the new bellow into position, ensuring the 3-inch side is on the riser and the 4-inch side is on the elbow.
7. Tighten Clamps: Position the clamps correctly over the connection points and tighten them securely. Do not overtighten, as this can damage the bellow.
8. Final Check: Reconnect the battery, start the engine, and carefully check for any signs of exhaust or water leaks around the new bellow.

Troubleshooting & FAQ

How do I know if this exhaust bellow fits my MerCruiser engine?
This bellow fits specific MerCruiser models from 1982-2002 with a "wet joint" exhaust system. It is compatible with 4-Cylinder (120/140HP, 3.0L), V6 (175-205HP), and V8 (200-370HP) engines. Please verify your model and year in the compatibility table and ensure your system uses a 3-inch center riser connecting to a 4-inch elbow.

What are the signs that my exhaust bellow needs replacement?
Common signs of a failing exhaust bellow include visible cracks, splits, or perishing of the rubber. You may also notice water leaking into the engine bilge from the exhaust area or hear an unusual amount of exhaust noise in the engine compartment.

Is this part for a "wet joint" or "dry joint" system?
This part is specifically designed for wet joint exhaust systems, which were standard on MerCruiser engines from 1983 to 2002. It is not compatible with the "dry joint" systems that were introduced after 2002.

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.