Gasket, Mount Case Cover – Fits Suzuki Outboard 70-140 HP (Replaces 51123-87L00)
Gasket, Mount Case Cover – Fits Suzuki Outboard 70-140 HP (Replaces 51123-87L00) is backordered and will ship as soon as it is back in stock.
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Delivery and Shipping
Delivery and Shipping
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Gasket, Mount Case Cover – Fits Suzuki Outboard 70-140 HP (Replaces 51123-87L00) is backordered and will ship as soon as it is back in stock.
Product Details
This replacement Gasket, Mount Case Cover – Fits Suzuki Outboard 70-140 HP (Replaces 51123-87L00) is designed for a precise fit on Suzuki 4-Stroke outboard models including the DF70, DF80, DF90, DF100, DF115, and DF140 series from 2009 through 2023. It ensures a proper seal for the engine's mount case cover, preventing leaks and maintaining performance.
This part is a direct replacement for Suzuki OEM part numbers 51123-87L00 and 51123-87L00-000.
- Installs on the engine mount case cover.
- Engineered with OEM-specified gasket material for durability.
- Compatible with all standard marine fuel types.
Part Number Matrix
Use this matrix to confirm equivalent references across OEM and aftermarket.
| Brand | Part Number |
|---|---|
| Suzuki | 51123-87L00 |
| Suzuki | 51123-87L00-000 |
Engine & Model Compatibility
Confirm your engine model/year in the table below.
Fitment is for specific Suzuki DF series 4-stroke outboards. Please verify your model and year range before ordering.
| Brand | Model | Rated HP | Stroke | Years | OEM Part No. |
|---|---|---|---|---|---|
| Suzuki | DF70A | 70 | 4-Stroke | 2009–2023 | 51123-87L00 |
| Suzuki | DF70ATH | 70 | 4-Stroke | 2009–2023 | 51123-87L00 |
| Suzuki | DF80A | 80 | 4-Stroke | 2009–2023 | 51123-87L00 |
| Suzuki | DF90A | 90 | 4-Stroke | 2009–2023 | 51123-87L00 |
| Suzuki | DF90ATH | 90 | 4-Stroke | 2009–2023 | 51123-87L00 |
| Suzuki | DF100B | 100 | 4-Stroke | 2009–2023 | 51123-87L00 |
| Suzuki | DF115 | 115 | 4-Stroke | 2009–2023 | 51123-87L00 |
| Suzuki | DF140 | 140 | 4-Stroke | 2009–2023 | 51123-87L00 |
Technical Specs
- Product Type
- Gasket
- Installation
- Engine Mount Case Cover
- Fuel Type
- Compatible with all fuel types
- Housing Material
- OEM-specified gasket material
- Dimensions
- 18.0" L x 15.0" W x 1.0" H
- Other Technical Attributes
- Meets OEM Specifications
What’s in the Box
- 1 x Gasket, Mount Case Cover (51123-87L00)
Installation Notes
- Disconnect the engine's battery as a safety precaution.
- Gain clear access to the mount case cover on the outboard.
- Carefully and evenly loosen and remove the fasteners securing the cover.
- Remove the old gasket. Thoroughly clean any old gasket material or residue from both the cover and the engine block mating surfaces.
- Position the new gasket correctly onto the engine block.
- Re-install the mount case cover, ensuring the gasket is not pinched or misaligned.
- Tighten the fasteners in a staggered pattern to the manufacturer's recommended torque specifications.
- Reconnect the battery, start the engine, and inspect carefully for any signs of leaks.
Troubleshooting & FAQ
How do I know if this gasket fits my Suzuki outboard?
This gasket is specifically designed for Suzuki 4-Stroke DF70A, DF80A, DF90A, DF100B, DF115, and DF140 models from 2009 to 2023. The best way to confirm fitment is to check your engine model and year against our compatibility table and verify that your old part number matches the interchange list (51123-87L00 or 51123-87L00-000).
What are the signs of a failing mount case cover gasket?
Common signs of a bad gasket include visible oil or water leaks around the mount case cover area, engine overheating, or a noticeable drop in performance. A visual inspection for residue or active drips is the most effective diagnostic method.
Can I reuse my old gasket after removing the cover?
No. Gaskets are designed for a single use. They compress and form a seal which is broken upon removal. Reusing an old gasket will almost certainly result in leaks and potential engine damage.
Is any sealant required with this gasket?
This gasket is typically designed to be installed dry, without any additional sealants. Always consult your engine's service manual for specific procedures, but in most cases, applying sealant can interfere with proper sealing.
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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