Exhaust Inner Cover Gasket – Fits Yamaha/Mercury 40HP 2-Stroke (Replaces 6F5-41112-A0, 27-11754)

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Product Details

This aftermarket Exhaust Inner Cover Gasket is designed for select Yamaha and Mercury 40HP 2-Stroke outboard motors, including Yamaha E40 and 40-series models from 2003–2004. It ensures a proper seal for the exhaust inner cover, a critical component for engine performance and safety.

It serves as a direct interchange for Yamaha part number 6F5-41112-A0 and Mercury part numbers 27-11754, 11754, and 11754M.

Installation Type: Direct Replacement
Housing Material: High-quality paper composite
Engine Location: Fits at position #38 of the engine block assembly

Part Number Matrix

Use this matrix to confirm equivalent references across OEM and aftermarket.

Brand	Part Number	Notes
Yamaha	6F5-41112-A0
Mercury / Mariner	27-11754	Also listed as 11754, 11754M

Engine & Model Compatibility

Confirm your engine model/year in the table below.

Fits the following 2-stroke Yamaha 40 HP models from 2003–2004.

Brand	Model	Rated HP	Stroke	Years	OEM Part No.
Yamaha	E40GMH/S/L	40	2-Stroke	2003–2004	6F5-41112-A0
Yamaha	E40JMH	40	2-Stroke	2003–2004	6F5-41112-A0
Yamaha	E40JWH	40	2-Stroke	2003–2004	6F5-41112-A0
Yamaha	40GWH	40	2-Stroke	2003–2004	6F5-41112-A0
Yamaha	40JWH	40	2-Stroke	2003–2004	6F5-41112-A0

Technical Specs

Product Type: Exhaust Inner Cover Gasket
Installation: Direct Replacement
Fuel Type: Gasoline
Housing Material: Paper
Dimensions: 25.5 cm L × 15.0 cm W × 0.3 cm H
Weight: 50g (0.11 lb)
Other Technical Attributes: Located at position #38 of the engine block assembly

What’s in the Box

1 × Exhaust Inner Cover Gasket (6F5-41112-A0/27-11754)

Installation Notes

Ensure the engine is off, cool, and the battery is disconnected for safety.
Locate and remove the exhaust cover to access the gasket. Refer to your service manual for component diagrams.
Carefully remove the old, worn gasket. Take care not to scratch the metal mating surfaces.
Thoroughly clean both the engine block and cover surfaces, removing all old gasket material and carbon residue.
Position the new gasket correctly on the engine block. Gaskets are typically installed dry unless your manual specifies a sealant.
Reinstall the exhaust cover and tighten the bolts in a crisscross pattern to the manufacturer's specified torque.

Troubleshooting & FAQ

How do I know if my exhaust cover gasket is failing?

Signs include a visible exhaust leak (smoke or soot) around the cover, an unusual ticking or hissing sound from the engine area, or an unexplained loss of engine performance.

Can I reuse my old gasket?

No. Gaskets provide a single-use seal by crushing into place. Reusing an old gasket will likely result in an improper seal, leading to exhaust leaks and potential engine damage.

What is the recommended replacement interval?

Inspect the gasket during regular engine service intervals. It must be replaced any time the exhaust cover is removed for service and should be replaced immediately if you detect any signs of wear, brittleness, or leakage.

Does this gasket fit both Yamaha and Mercury models?

Yes, this part is cross-compatible and serves as a direct aftermarket replacement for both Yamaha 6F5-41112-A0 and Mercury 27-11754 on the specified 40HP 2-Stroke engines.

Is any sealant required for installation?

Generally, paper gaskets like this are designed to be installed dry. Always consult your engine's service manual for specific recommendations. Applying a thin layer of a suitable gasket sealant may be advised for surfaces with minor imperfections, but is not always necessary.

OEM vs. Aftermarket?

This listing is an aftermarket replacement (not OEM). Built to OEM-level specifications with comparable materials. Manufactured in an ISO 9002 facility, batch-inspected for consistency.

Shipping speed & cost

We ship worldwide quickly—typical transit 5–15 days. Standard shipping is free; expedited options appear at checkout where available.

Warranty & returns

Covered by a 1-year warranty against manufacturing defects under normal use. If issues arise, contact support with your order details. Returns are accepted within our standard window (unused & in original condition). See our policy page or reach out for instructions.

Safety & Important Info

Verify images/specifications vs your original part. If anything differs—even if your model appears compatible—do not purchase.
This is an aftermarket replacement, not an OEM component.
Professional installation is recommended for safety and performance.

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