78458A1 Exhaust Tube Bellow for MerCruiser | JLM Marine

Exhaust Tube Bellow for MerCruiser – Fits Alpha One, Bravo & Blackhawk Drives

This exhaust tube bellow is engineered to meet or exceed OEM specifications for MerCruiser stern drive applications. Designed for R/MR/Alpha One (Serial No. 6225577 & UP, 1983-1990), Bravo I, II, III (Serial No. OB664190 & UP, 1988 and later), and Blackhawk (Serial No. 0F18677 & UP, 1994-1995) drives, this bellow ensures reliable exhaust routing and protection in demanding marine environments.

Direct Replacements: 78458A1, 18-2760, 9-72810, 89150

• Comes complete with stainless steel clamp as shown
• Built to OEM dimensions for precise fitment
• Suitable for long-term durability in saltwater and freshwater applications

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 × Exhaust Tube Bellow (exactly as shown)
• 1 × Stainless Steel Clamp

Installation Guide

1. Disconnect the battery and raise the stern drive to access the bellows assembly.
2. Remove the old exhaust bellow by loosening and removing the stainless clamps at both ends.
3. Inspect the exhaust tube and mounting surfaces for cracks, corrosion, or damage; clean thoroughly.
4. Slide the new bellow onto the exhaust tube, ensuring it seats fully on both the gimbal housing and drive unit connections.
5. Position the stainless clamps over the bellow ends and tighten securely using a screwdriver or socket wrench.
6. Verify that the bellow is not twisted or kinked and that clamps are snug but not over-tightened.
7. Lower the drive unit and reconnect the battery. Run the engine briefly and check for exhaust leaks around the bellow.
8. Re-inspect clamp tightness after the first few hours of operation.

Troubleshooting & FAQ

Q: How do I confirm this fits my MerCruiser drive?
A: Check your stern drive's serial number plate. This bellow fits R/MR/Alpha One (Serial 6225577 & up, 1983-1990), Bravo I/II/III (Serial OB664190 & up, 1988+), and Blackhawk (Serial 0F18677 & up, 1994-1995). Compare the images with your original part to ensure a match.

Q: How often should I replace the exhaust bellow?
A: Inspect bellows annually for cracks, tears, or hardening. Replace every 3–5 years or immediately if you notice exhaust leaks, water intrusion, or visible damage.

Q: What are signs the exhaust bellow is failing?
A: Common symptoms include visible cracks or splits in the rubber, water in the bilge near the stern drive, exhaust fumes in the engine compartment, or a burning smell during operation.

Q: Does this come with installation hardware?
A: Yes, the bellow includes one stainless steel clamp as shown in the product images. You may need additional clamps depending on your drive configuration; refer to your service manual.

Q: Is this an OEM MerCruiser part or 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.