60930 Exhaust Flapper Water Shutter & Grommets for Mercruiser 2.5L 3.0L 3.0LX 3.7L 3.7LX | JLM Marine

Exhaust Flapper Water Shutter & Grommets for Mercruiser 2.5L 3.0L 3.0LX 3.7L 3.7LX

This exhaust flapper water shutter assembly with retaining grommets is designed for Mercruiser 2.5L, 3.0L, 3.0LX, 3.7L, and 3.7LX inline 4-cylinder exhaust systems. The shutter helps prevent water from running back into the engine under certain operating conditions, providing essential protection for your powerhead.

Direct replacement for: Mercruiser 60930 & 27-43809, Sierra 18-2727, and EMP 32-08302 & MC 25-43809.

• Includes exhaust water shutter and retaining grommets for complete installation
• Prevents water backflow into engine during specific operating conditions
• New in package with manufacturer's warranty

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

• Exhaust flapper water shutter (1 piece)
• Retaining grommets

Installation Guide

1. Ensure the engine is off and cool before beginning work. Disconnect the battery to prevent accidental starts.
2. Locate the exhaust flapper housing on your Mercruiser exhaust manifold or riser assembly. Remove any components blocking access if necessary.
3. Carefully remove the old water shutter and inspect the housing for debris, corrosion, or damage. Clean the mounting surface thoroughly.
4. Install the new retaining grommets into the designated slots in the housing. Ensure they are seated properly and not twisted.
5. Position the new exhaust flapper water shutter into the housing, aligning it with the grommet slots. The flapper should move freely and seat flat when closed.
6. Verify that the shutter opens and closes smoothly without binding. Check that all grommets remain in place during movement.
7. Reinstall any components removed for access and reconnect the battery. Start the engine and check for proper exhaust flow and water discharge.
8. Inspect for any water leaks or abnormal exhaust behavior during initial operation. Shut down immediately if issues are detected.

Troubleshooting & FAQ

Q: How do I confirm this exhaust flapper fits my Mercruiser engine?
A: Cross-reference your engine's model, horsepower, and serial number with the compatibility table above. Verify that your original part number matches 60930, 27-43809, or the equivalent Sierra/EMP numbers listed.

Q: What are the signs that my exhaust water shutter needs replacement?
A: Common symptoms include water backflow into the exhaust manifold, difficulty starting after the boat has been sitting, excessive water in the cylinders, or visible damage/deterioration of the rubber flapper or grommets.

Q: How often should I replace the exhaust flapper water shutter?
A: Inspect the flapper and grommets annually or every 100 hours of operation. Replace immediately if you notice cracks, stiffness, loss of flexibility, or if the flapper no longer seals properly.

Q: Can I install this myself or do I need a professional?
A: Installation is straightforward for those with basic mechanical skills and familiarity with marine engines. However, professional installation is recommended to ensure proper fitment, prevent water intrusion issues, and maintain warranty coverage.

Q: What's the difference between OEM and this aftermarket exhaust flapper?
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.