Exhaust Bellows – Fits Mercruiser Alpha One & Bravo Drives (Replaces 18654A1, 32734A3)

Exhaust Bellows – Fits Mercruiser Alpha One & Bravo Drives (Replaces 18654A1, 32734A3)

This replacement exhaust bellows is designed for a wide range of MerCruiser stern drives, including Alpha One Gen I (1983–1990), Alpha One Gen II (1991–Current), and Bravo I, II, & III models. It is also compatible with #1, R, MR, TRS, and Blackhawk drives from 1978 onward.

It serves as a direct replacement for Mercury part numbers 18654A1, 32734A3, 18654B1, and 8M0124227, as well as aftermarket parts from Sierra (18-2750) and GLM (89100).

• Engineered for direct installation on compatible MerCruiser drives.
• Constructed from durable rubber to withstand the marine environment.
• Secured with included stainless steel hose clamps for a reliable seal.

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.

Technical Specifications

Package Contents

• 1 x Exhaust Bellow (Replaces 18654A1/8M0124227)
• 2 x Hose Clamps (stainless steel)

Installation Guide

Follow these steps to replace your exhaust bellows. Professional installation is recommended.

1. Safety First: Turn off the engine and allow it to cool completely. Disconnect the boat's battery.
2. Access the Bellows: Trim the sterndrive up to provide access to the exhaust bellows located on the transom assembly.
3. Remove Old Clamps: Loosen and remove the two hose clamps securing the old bellows at both ends.
4. Remove Old Bellows: Carefully pull the old bellows off the transom housing and the bell housing. This may require some force if it's old and stiff.
5. Clean Surfaces: Thoroughly clean the mounting grooves on both the transom and bell housings to ensure a clean, debris-free sealing surface.
6. Install New Bellows: Position the new bellows, ensuring it is correctly seated in the grooves at both ends.
7. Secure New Clamps: Place the new stainless steel clamps over the bellows in the proper groove and tighten them securely. Do not overtighten, as this can damage the rubber.
8. Final Check: Lower the sterndrive, reconnect the battery, and start the engine. Check for any exhaust or water leaks around the new bellows before operating the vessel.

Troubleshooting & FAQ

Q: How do I confirm this fits my Mercruiser drive?

A: First, check the detailed compatibility table on this page to ensure your specific drive model (e.g., Alpha One Gen I, Bravo II) and year range are listed. You can also verify by cross-referencing the part number stamped on your old bellows with the OEM and aftermarket numbers we provide, such as 18654A1, 32734A3, and Sierra 18-2750.

Q: What are the signs my exhaust bellows is failing?

A: The most common indicators of a failing bellows are visible cracks, splits, or dry, brittle rubber. Functionally, a failure can lead to loud exhaust noises from the stern or, more critically, water leaking into the bilge through the transom assembly.

Q: How often should I replace the exhaust bellows?

A: As a critical component for preventing water intrusion, exhaust bellows should be inspected annually for any signs of wear or damage. For preventative maintenance, it is recommended to replace them every 3-5 years, even if they appear visually intact.

Q: What is included in this kit?

A: This kit includes everything needed for a standard replacement: one high-grade rubber exhaust bellow and two corresponding stainless steel hose clamps.

Q: OEM vs. Aftermarket?

A: 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.

Q: How fast do you ship and how much does it cost?

A: 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.

Q: What is your warranty and return policy?

A: 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.