Manifold To Elbow Gasket for Volvo Penta OMC | JLM Marine
This Exhaust Manifold to Elbow Gasket is engineered for Volvo Penta and OMC Cobra stern drive marine engines, specifically the 3.0L GM platform. It provides a reliable seal between the exhaust manifold and elbow riser assembly, preventing exhaust leaks and ensuring optimal engine performance.
Direct Replacements: Volvo Penta 3850495, OMC Cobra 778045 & 908013, Sierra 18-2875. This aftermarket gasket meets OEM specifications and offers dependable fitment across multiple manufacturers.
- Designed for stern drive marine engine applications
- Prevents exhaust leaks and maintains proper sealing under high temperatures
- Simple installation between manifold and elbow riser
Part Number Cross-Reference
Use this table to confirm equivalent part numbers across OEM and aftermarket brands.
| Brand |
Part Number |
| Volvo Penta |
3850495 |
| OMC Cobra |
778045 |
| OMC Cobra |
908013 |
| Sierra |
18-2875 |
Compatible Engine Models
Confirm your engine model/year in the table below.
| Brand |
Model |
Rated HP |
Notes |
| Volvo Penta |
3.0L GM (GS, GL, GLM, GLP, GSM, GSP) |
- |
Block manifolds, elbows & gaskets |
| OMC Cobra |
4 cyl. 153CID / 2.5L GM (1981-1986) |
120 HP |
Manifolds, elbows, end caps & gaskets |
| OMC |
4 cyl. 181CID / 3.0L GM (1973-1990) |
140 HP |
Manifolds, elbows, end caps & gaskets |
Technical Specifications
| Specification |
Value |
| OEM Number |
3850495 |
| Application |
Exhaust Manifold to Elbow Riser |
| Engine Type |
Stern Drive Marine Engines |
| Primary Fitment |
Volvo Penta & OMC Cobra 3.0L GM |
Package Contents
Your purchase includes:
- 1 × Exhaust Manifold to Elbow Gasket
Installation Guide
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Preparation: Ensure the engine is cool and disconnect the battery to prevent accidental ignition.
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Access the Manifold: Remove any components obstructing access to the exhaust manifold and elbow riser assembly.
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Disconnect the Elbow: Carefully unbolt and separate the exhaust elbow from the manifold. Support the elbow to prevent damage.
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Remove Old Gasket: Thoroughly clean both mating surfaces, removing all remnants of the old gasket and any carbon buildup using a gasket scraper and solvent.
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Inspect Surfaces: Check both the manifold and elbow surfaces for warping, cracks, or corrosion that may compromise the seal.
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Position New Gasket: Place the new gasket onto the manifold, aligning all bolt holes precisely.
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Reattach Elbow: Carefully position the elbow riser onto the gasket and hand-thread all mounting bolts to ensure proper alignment.
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Torque Bolts: Tighten the bolts in a crisscross pattern to the manufacturer's specified torque settings to ensure even compression.
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Reinstall Components: Replace any removed components and reconnect all hoses and fittings securely.
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Reconnect Battery: Restore electrical connections once all mechanical work is complete.
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Test Run: Start the engine and inspect the gasket area carefully for any exhaust leaks during operation.
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Final Check: After a short test run, re-check bolt torque and inspect for leaks once more before returning to regular use.
Troubleshooting & FAQ
Q: How do I confirm this gasket fits my engine?
A: Cross-reference your engine's model and year with the Compatible Engine Models table above. Verify that your original gasket matches the dimensions and bolt hole pattern shown in the product images. If you have a Volvo Penta 3.0L GM or OMC Cobra 2.5L/3.0L stern drive engine, this gasket should fit.
Q: What are the signs that my manifold-to-elbow gasket needs replacement?
A: Common symptoms include visible exhaust leaks at the manifold/elbow joint, hissing or popping sounds during operation, excessive corrosion around the connection, or water entering the exhaust system. Replace the gasket immediately if you detect any of these issues to prevent engine damage.
Q: How often should I replace this gasket?
A: Inspect the gasket annually or whenever you service the exhaust system. Replace it if you notice any deterioration, leaks, or when removing the elbow for other maintenance. As a preventive measure, many marine technicians recommend replacing exhaust gaskets every 3–5 years or whenever manifolds/elbows are serviced.
Q: Can I reuse the old gasket if it looks intact?
A: No, exhaust gaskets are designed for single use only. Once compressed, the gasket material loses its sealing properties and will not provide a reliable seal if reinstalled. Always use a new gasket when separating and reassembling the manifold and elbow.
Q: What's the difference between this aftermarket gasket and the OEM version?
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?
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Quality Assured: As a trusted manufacturer for over 20 years, we supply top marine brands globally.
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Fast Global Shipping: Free delivery worldwide in 5–15 days.
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Direct from Manufacturer: Competitive pricing without compromising quality.