3852742;18-2781 Lower Exhaust Hose for OMC Cobra | JLM Marine

Lower Exhaust Hose for OMC Cobra 2.3L 5.0L 5.7L 5.8L – Replaces 3852742, 18-2781

This Lower Exhaust Hose is engineered for OMC Cobra sterndrive applications, fitting a range of engines from 2.3L to 5.8L across multiple model years. Designed to handle exhaust flow in demanding marine environments, this hose ensures reliable performance and durability for GM and Ford-based sterndrive systems, including cone clutch drives.

This aftermarket replacement directly replaces OEM part number 3852742 and Sierra part number 18-2781, offering a cost-effective solution without compromising on quality. It is compatible with various OMC Cobra configurations from the late 1980s through the early 1990s.

• Direct replacement for OMC 3852742 and Sierra 18-2781
• Fits 2.3L, 4.3L, 5.0L, 5.7L, and 5.8L sterndrive engines
• Suitable for cone clutch drives including 350, 454, and 460 King models

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 Lower Exhaust Hose (3 1/2" x 3 1/2")

Installation Guide

1. Disconnect the battery and allow the engine to cool completely before beginning work.
2. Access the lower exhaust hose by removing any necessary engine covers or components that obstruct the sterndrive assembly.
3. Carefully disconnect any clamps or fasteners securing the old exhaust hose to the sterndrive and engine block.
4. Remove the old exhaust hose, noting its orientation and routing for proper installation of the replacement.
5. Inspect the connection points for corrosion, damage, or debris, and clean thoroughly before proceeding.
6. Position the new exhaust hose in the same orientation as the original, ensuring a proper fit at both ends.
7. Secure the hose using marine-grade clamps at both connection points, tightening to manufacturer specifications.
8. Double-check that the hose is not kinked, twisted, or obstructed and has adequate clearance from moving parts.
9. Reinstall any components or covers removed during disassembly.
10. Reconnect the battery and perform a visual inspection for proper seating and alignment.
11. Start the engine and allow it to run at idle, checking for exhaust leaks or unusual vibrations.
12. If any issues are detected, shut down the engine immediately and re-inspect all connections and clamp tightness.

Troubleshooting & FAQ

Q: How do I confirm this exhaust hose fits my OMC Cobra sterndrive?
A: Verify your engine's displacement (2.3L, 4.3L, 5.0L–5.8L, etc.) and model year against the compatibility table above. Cross-reference your original part number (3852742 or 18-2781) to ensure a proper match.

Q: What are the signs that my lower exhaust hose needs replacement?
A: Common indicators include visible cracks or splits in the hose, exhaust leaks at idle or under load, excessive vibration, or water intrusion into the exhaust system. Replace immediately if any damage is observed.

Q: Can I install this hose myself, or do I need a professional?
A: Installation requires moderate mechanical skill and access to the sterndrive assembly. If you are comfortable working with marine engines and have the proper tools, DIY installation is possible. Otherwise, professional installation is recommended.

Q: How often should I replace the lower exhaust hose?
A: Inspect the exhaust hose annually as part of routine maintenance. Replace it if you observe cracks, hardening, or any signs of wear. Typical service life varies based on operating conditions and engine usage.

Q: Is this an OEM part or an aftermarket replacement?
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.