Sea Water Pump Impeller Kit – Fits OMC Cobra 3.0-5.8L (Replaces 87203K, 983895)
Sea Water Pump Impeller Kit – Fits OMC Cobra 3.0-5.8L (Replaces 87203K, 983895) is backordered and will ship as soon as it is back in stock.
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Worry-free returns
You may return most new, unopened items within 7 days of delivery for a full refund. We'll also pay the return shipping costs if the return is a result of our error (you received an incorrect or defective item, etc.).
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Delivery and Shipping
Delivery and Shipping
Free standard shipping on all orders under 1 KG
Sea Water Pump Impeller Kit – Fits OMC Cobra 3.0-5.8L (Replaces 872...
Product Details
This Sea Water Pump Impeller Kit is designed for OMC Cobra 3.0L, 4.3L, 5.0L, 5.7L, and 5.8L stern drives manufactured between 1986 and 1993. It is specifically engineered for models equipped with belt-driven sea water pumps that use a splined shaft connection.
It serves as a direct replacement for several part numbers, including OMC 87203K, OMC/Volvo 983895, Sierra 18-3058, QuickMarine 0983895, and QuickMariner 18-3348.
- Fits belt-driven water pumps with a splined shaft.
- Restores cooling system performance to prevent overheating.
- Kit includes the impeller, wear plate, O-ring, and gasket for a complete service.
Part Number Matrix
Use this matrix to confirm equivalent references across OEM and aftermarket.
| Brand | Part Number |
|---|---|
| OMC | 87203K |
| OMC/Volvo | 983895 |
| Sierra | 18-3058 |
| QuickMarine | 0983895 |
| QuickMariner | 18-3348 |
Engine & Model Compatibility
Confirm your engine model/year in the table below.
For OMC/Volvo owners, this kit fits Cobra SX models from 1986 to 1993 with the specific splined shaft pump. Please verify your pump type before ordering.
| Brand | Model | Rated HP | Stroke | Years | OEM Part No. | Notes |
|---|---|---|---|---|---|---|
| OMC | Cobra SX | 3.0L | 4-Stroke | 1986–1993 | 87203K | Splined shaft pump only |
| OMC | Cobra SX | 3.5L | 4-Stroke | 1986–1993 | 87203K | Splined shaft pump only |
| OMC | Cobra SX | 3.8L | 4-Stroke | 1986–1993 | 87203K | Splined shaft pump only |
| OMC | Cobra SX | 4.3L | 4-Stroke | 1986–1993 | 87203K | Splined shaft pump only |
| OMC | Cobra SX | 5.0L | 4-Stroke | 1986–1993 | 87203K | Splined shaft pump only |
| OMC | Cobra SX | 5.7L | 4-Stroke | 1986–1993 | 87203K | Splined shaft pump only |
| OMC | Cobra SX | 5.8L | 4-Stroke | 1986–1993 | 87203K | Splined shaft pump only |
Technical Specs
- Product Type
- Sea Water (Raw Water) Pump Impeller Kit
- Installation
- Belt-driven water pump (splined shaft type)
- Connection
- Splined shaft
- Fitting Type
- Splined shaft
- Other Technical Attributes
- Fits Cobra SX belt-driven water pumps
What’s in the Box
- 1 x Impeller
- 1 x Wear Plate
- 1 x O-Ring
- 1 x Gasket
Installation Notes
- Disconnect the battery and close the engine's water inlet seacock.
- Loosen the drive belt and remove the water pump cover/housing. Note the orientation of the bolts.
- Use pliers or an impeller puller to remove the old impeller. Note the rotational direction of the old blades.
- Clean the inside of the pump housing thoroughly, removing any old gasket material or debris.
- Install the new gasket or O-ring, ensuring a clean, dry seal.
- Lightly lubricate the new impeller with water-based lubricant and insert it while turning the shaft in the direction of engine rotation to bend the vanes correctly.
- Re-install the pump cover, tighten the bolts to the manufacturer's specified torque, and re-tension the drive belt.
- Open the seacock, reconnect the battery, start the engine, and immediately check for leaks and proper water flow.
Troubleshooting & FAQ
How do I know if this impeller fits my OMC Cobra?
This kit fits specific OMC Cobra stern drives (3.0L to 5.8L) from 1986–1993 that use a belt-driven pump with a splined shaft. It will not fit models with keyed shafts. Please verify your pump configuration before ordering.
What are the signs of a failing water pump impeller?
Common signs include higher-than-normal engine operating temperatures, reduced water flow from the exhaust, visible cracks or missing vanes on the old impeller, and a stiff or brittle feel to the rubber.
How often should I replace my impeller?
For preventative maintenance, most manufacturers recommend replacing the impeller every 1-2 seasons or every 100-200 hours of operation, whichever comes first. Refer to your engine's service manual for specific intervals.
What happens if the impeller fails while operating the engine?
An impeller failure will stop the flow of raw cooling water to the engine, leading to rapid overheating. This can cause severe engine damage, including cracked heads or a seized engine. Always monitor your temperature gauge.
Is the housing cup included in this kit?
This specific kit includes the core service components: impeller, wear plate, gasket, and O-ring. A separate housing cup is not included, as it is often reusable if not damaged.
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.
Payment & Security
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