Bearing – Fits Yamaha 4HP/5HP/6HP/8HP 2-Stroke Outboards (Replaces 93310-112V0-00, 31-91721M)
Bearing – Fits Yamaha 4HP/5HP/6HP/8HP 2-Stroke Outboards (Replaces 93310-112V0-00, 31-91721M) is backordered and will ship as soon as it is back in stock.
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Delivery and Shipping
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Bearing – Fits Yamaha 4HP/5HP/6HP/8HP 2-Stroke Outboards (Replaces ...
Product Details
This is a replacement Bearing – Fits Yamaha 4HP/5HP/6HP/8HP 2-Stroke Outboards, specifically designed for models made between 1985 and 2003. It also fits a range of rebranded Mercury/Mariner 4HP to 8HP engines from the same era. This component serves as the crankshaft bearing located at position #10 in the cylinder assembly.
It is a direct interchange for Yamaha part number 93310-112V0-00, Mercury/Mariner 31-91721M, and EMP 31-31511.
- Installation: Internal engine component requires a press fit.
- Includes: One crankshaft cylinder bearing.
- Position: Confirmed as cylinder bearing #10 in the engine block assembly.
Part Number Matrix
Use this matrix to confirm equivalent references across OEM and aftermarket.
| Brand | Part Number |
|---|---|
| Yamaha | 93310-112V0-00 |
| Mercury/Mariner | 31-91721M |
| EMP | 31-31511 |
Engine & Model Compatibility
Confirm your engine model/year in the table below.
For Yamaha Owners: This bearing fits a range of small 2-stroke outboards from the mid-80s through the early 2000s, including popular 4AC, 5C, 6D, and 8C models.
For Mercury/Mariner Owners: This part is for rebranded Yamaha-built 2-stroke engines. Check your model and year to ensure it aligns with the compatible series.
| Brand | Model | Rated HP | Stroke | Years | OEM Part No. | Notes |
|---|---|---|---|---|---|---|
| Yamaha | 4AC | 4 | 2-Stroke | 1985–2002 | 93310-112V0-00 | |
| Yamaha | 4AS | 4 | 2-Stroke | 1987–1996 | 93310-112V0-00 | |
| Yamaha | 4MSH | 4 | 2-Stroke | 1985–2002 | 93310-112V0-00 | |
| Yamaha | 4KZ | 4 | 2-Stroke | 1985–2002 | 93310-112V0-00 | |
| Yamaha | 5C | 5 | 2-Stroke | 1994–1998 | 93310-112V0-00 | |
| Yamaha | 5CS | 5 | 2-Stroke | 1994–1996 | 93310-112V0-00 | |
| Yamaha | 6C | 6 | 2-Stroke | 1990–2001 | 93310-112V0-00 | |
| Yamaha | 6D | 6 | 2-Stroke | 1990–1998 | 93310-112V0-00 | |
| Yamaha | 8C | 8 | 2-Stroke | 1987–2003 | 93310-112V0-00 | |
| Mercury/Mariner | 4HP | 4 | 2-Stroke | 1985–2002 | 31-91721M | Rebranded Yamaha engines |
| Mercury/Mariner | 5HP | 5 | 2-Stroke | 1994–1998 | 31-91721M | Rebranded Yamaha engines |
| Mercury/Mariner | 6HP | 6 | 2-Stroke | 1990–2001 | 31-91721M | Rebranded Yamaha engines |
| Mercury/Mariner | 8HP | 8 | 2-Stroke | 1987–2003 | 31-91721M | Rebranded Yamaha engines |
Technical Specs
- Product Type
- Bearing, Crankshaft (Cylinder)
- Installation
- Internal engine component
- Connection
- Press fit
- Fitting Type
- Press fit
- Dimensions (Approximate)
- 1.0" H x 10.0" W x 9.0" L
- Other Technical Attributes
- Position #10 in cylinder assembly
What’s in the Box
- 1 x Bearing (93310-112V0-00)
Installation Notes
- Professional installation is strongly recommended for this internal engine component.
- Begin by completely draining all engine oil and fuel.
- Carefully disassemble the engine block according to your model's service manual to access the crankshaft assembly.
- Use a suitable bearing press tool to remove the old bearing from its housing. Do not use a hammer or brute force, which can damage the crankshaft or block.
- Clean the bearing seat thoroughly and inspect for any damage or scoring.
- Press the new bearing into place, ensuring it is properly aligned and fully seated.
- Reassemble the engine, following the service manual's torque specifications and procedures.
- Refill with fresh engine oil before attempting to start the engine.
Troubleshooting & FAQ
How do I confirm this bearing is the right one for my motor?
The most reliable method is to match your engine's model and year to our compatibility table. You can also cross-reference your existing part number with the ones listed in the Part Number Matrix. When in doubt, consult your service manual.
What are the signs of a failing crankshaft bearing?
Common symptoms include a knocking or rumbling noise from the engine that changes with RPM, excessive engine vibration, or the presence of metallic shavings in the engine oil during a change. These signs indicate a need for immediate inspection.
This is position #10. Are there other bearings I should replace at the same time?
Yes, crankshafts typically have multiple support bearings. It is best practice to replace all of them as a set during an engine rebuild to ensure even wear and longevity. Please consult your engine's service manual for a complete list of required bearings and their locations.
Why do Yamaha and Mercury/Mariner use different part numbers for the same bearing?
This part was used in Yamaha engines that were also sold under the Mercury and Mariner brands. Each company assigned its own unique part number for inventory and service purposes, even though the underlying component is identical.
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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