Exhaust Cover Gasket – Fits Yamaha/Mariner 6HP & 8HP 2-Stroke Outboards (Replaces 677-41112-A0)
Exhaust Cover Gasket – Fits Yamaha/Mariner 6HP & 8HP 2-Stroke Outboards (Replaces 677-41112-A0) is backordered and will ship as soon as it is back in stock.
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Worry-free returns
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Delivery and Shipping
Delivery and Shipping
Free standard shipping on all orders under 1 KG
Exhaust Cover Gasket – Fits Yamaha/Mariner 6HP & 8HP 2-Stroke O...
Product Details
This is a direct-replacement Exhaust Cover Gasket designed for Yamaha 6HP and 8HP 2-stroke outboards, specifically the 6B and 8B models with serial numbers beginning in "677". It also fits certain older Japanese Domestic Market (JDM) Yamaha models and select Mariner 8HP–15HP 2-stroke outboards manufactured in Japan.
It directly replaces Yamaha part numbers 677-41112-A0, 677-41112-A1, 677-41112-A200, 677-41114-A0, and 677-41114-A1, as well as Mariner/Mercury equivalents 27-95597M and 95597M.
- Engineered for a direct fit and easy installation.
- Designed for gasoline-powered 2-stroke outboard engines.
- Seals the exhaust inner cover to prevent leaks.
Part Number Matrix
Use this matrix to confirm equivalent references across OEM and aftermarket.
| Brand | Part Number | Notes |
|---|---|---|
| Yamaha | 677-41112-A0 | |
| Yamaha | 677-41112-A1 | Supersedes 677-41112-A0 |
| Yamaha | 677-41112-A200 | Supersedes 677-41112-A1 |
| Yamaha | 677-41114-A0 | |
| Yamaha | 677-41114-A1 | Supersedes 677-41114-A0 |
| Mariner/Mercury | 27-95597M | |
| Mariner/Mercury | 95597M |
Engine & Model Compatibility
Confirm your engine model/year in the table below.
For Yamaha, this part fits 6B and 8B models where the serial number starts with "677".
For Mariner, this gasket is only compatible with older outboards manufactured in Japan within the 8–15 HP range.
| Brand | Model | Rated HP | Stroke | OEM Part No. | Notes |
|---|---|---|---|---|---|
| Yamaha | 6B | 6 | 2-Stroke | 677-41112-A0 | Models with serial number starting with 677 |
| Yamaha | 8B | 8 | 2-Stroke | 677-41112-A0 | Models with serial number starting with 677 |
| Mariner | 8–15 | 2-Stroke | 27-95597M | Will fit only old Mariner, Japan models |
Technical Specs
- Product Type
- Exhaust Cover Gasket
- Application
- Seals exhaust inner cover
- Fuel Type
- Gasoline (2-stroke)
- Fitting Type
- Direct mount
- Dimensions
- 25.5 cm × 14.5 cm × 0.4 cm
- Weight
- 26g (0.057 lb)
- Package Contents
- Sold as individual gasket
What’s in the Box
- 1x Gasket, Exhaust Inner Cover (Replaces 677-41112-A0)
Installation Notes
- Disconnect the battery and ensure the engine is cool to the touch before beginning work.
- Locate and remove the outer exhaust cover housing to access the inner cover plate.
- Carefully remove the bolts securing the inner exhaust cover and lift it away from the engine block.
- Remove the old gasket and thoroughly clean both mating surfaces. Ensure all old gasket material and sealant residue are gone.
- Position the new gasket correctly over the alignment pins or bolt holes.
- Reinstall the inner exhaust cover, tightening the bolts in a crisscross pattern to the manufacturer's specified torque.
- Reattach the outer exhaust housing and reconnect the battery.
- Start the engine and check for any exhaust leaks around the cover.
Troubleshooting & FAQ
How do I know if this gasket fits my specific outboard?
This gasket is for specific Yamaha and Mariner models. For Yamaha, check if your model is a 6B or 8B with a serial number starting with "677". For Mariner, it fits older Japanese-made 8HP–15HP units. Always cross-reference your old part number with those listed in our Part Number Matrix.
What are the signs of a failing exhaust cover gasket?
Common signs include visible exhaust/water leaks around the cover, an unusually loud engine sound, a rough idle, or a loss of power. A visual inspection may reveal soot trails or corrosion where the leak is occurring.
Can I reuse my old gasket?
No. Gaskets are single-use components designed to crush and seal. Once compressed, they will not provide a reliable seal if reused. Always install a new gasket when a component is removed.
Is any sealant required for installation?
Generally, this type of gasket is installed dry. However, always consult your engine's service manual for specific recommendations. Applying sealant where it's not required can interfere with the seal or block passages.
What is the difference between an inner and outer exhaust cover gasket?
Engines often have multiple exhaust covers. This part is specifically for the inner cover, which mounts directly to the engine block. Ensure you are purchasing the correct gasket for the component you are servicing.
How often should this gasket be replaced?
This gasket does not have a set replacement interval. It should be replaced anytime the exhaust cover is removed for service, or if it shows signs of leaking or degradation.
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.
About Sea Sierra
- Pro-Grade Standards — We supply marine parts engineered to OEM-level tolerances and tested for real-world conditions.
- Fast Global Fulfillment — Free standard delivery to most regions in 5–15 days.
- Manufacturer-Direct Value — Fair pricing without compromising on materials or QC.
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