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)

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 made for models equipped with belt-driven water pumps that use a splined shaft.

This assembly is a direct replacement for the following OEM and aftermarket part numbers: OMC 87203K, OMC/Volvo 983895, Sierra 18-3058, QuickMarine 0983895, and QuickMariner 18-3348.

• Complete Kit: Includes the core components needed for a standard replacement: impeller, wear plate, o-ring, and gasket.
• Installation Type: Designed for engine-mounted, belt-driven sea water pumps.
• Connection Style: Features a splined shaft connection for secure fitting.

Part Number Cross-Reference

Use this table to confirm equivalent part numbers across OEM and aftermarket brands.

Compatible Engine Models

Confirm your engine model/year in the table below.

Technical Specifications

Package Contents

• 1 x Impeller
• 1 x Wear Plate
• 1 x O-Ring
• 1 x Gasket

Installation Guide

Follow these general steps to replace your sea water pump impeller. Professional installation is always recommended for safety and proper function.

1. Safety First: Disconnect the boat's battery before beginning any work.
2. Access the Pump: Locate the belt-driven sea water pump on the engine and relieve tension from the serpentine belt to remove it from the pump pulley.
3. Remove Hoses: Carefully disconnect the inlet and outlet water hoses from the pump housing. Be prepared for some residual water to spill out.
4. Unbolt the Pump: Remove the mounting bolts that secure the pump to the engine bracket and carefully detach the pump assembly.
5. Open the Housing: Remove the screws on the pump's rear cover to access the impeller. Note the orientation of the old impeller's blades before removal.
6. Replace Components: Remove the old o-ring/gasket, wear plate, and impeller. Clean the inside of the housing thoroughly.
7. Install New Parts: Place the new wear plate and o-ring/gasket into the housing. Lubricate the new impeller and housing interior with a suitable marine lubricant.
8. Insert Impeller: Carefully insert the new impeller, bending the vanes in the same direction as the original. An incorrect orientation will result in no water flow.
9. Reassemble Pump: Secure the housing cover with its screws, ensuring a tight seal.
10. Remount and Reconnect: Bolt the pump back onto the engine bracket, reconnect the water hoses, and reinstall the serpentine belt, ensuring it is properly tensioned.
11. Final Check: Reconnect the battery, start the engine, and immediately check for any water leaks around the pump housing and hoses. Verify water is exiting the exhaust.

Troubleshooting & FAQ

Q: How do I know if this impeller kit is for the splined shaft or keyed shaft pump?

A: This kit is specifically for the splined shaft version of the OMC Cobra belt-driven water pump, primarily used from 1986–1993. It will not fit keyed shaft models. Please verify your pump type before ordering.

Q: My engine is overheating. Could a bad impeller be the cause?

A: Yes, a worn or damaged impeller is a common cause of engine overheating. Signs of failure include brittle or broken vanes, a cracked hub, or visibly reduced water flow from the exhaust when the engine is running.

Q: How often should I replace the sea water pump impeller?

A: As a general maintenance rule, we recommend inspecting your impeller annually and replacing it every 1-2 years or every 100-200 hours of operation. Replacement frequency depends on usage conditions (e.g., saltwater vs. freshwater, high-debris areas).

Q: OEM vs. Aftermarket?

A: This listing is an aftermarket replacement part (not an OEM component). We build to OEM specifications using comparable-grade materials. Production is done in an ISO9002-certified facility, and each batch is inspected for consistent performance.

Q: How fast do you ship and how much does it cost?

A: We offer fast global shipping—typically 5–15 days worldwide—and standard shipping is free. Expedited options are available at checkout depending on your location.

Q: What is your warranty and return policy?

A: This product includes a 1-year warranty against manufacturing defects under normal use. If something goes wrong, contact our support team with your order details. Returns are accepted within our standard return window (unused & in original condition); please see our policy page or reach out for instructions.

Important Notes

• Verify that the product images and specifications match your original part. If discrepancies exist—even if your model is listed—do not proceed with the purchase.
• This product is an aftermarket replacement part and is not an OEM component.
• Professional installation is recommended to ensure safety and optimal performance.

Why Choose JLM MARINE?

• Quality Assured: As a trusted manufacturer for over 20 years, we supply top marine brands globally.
• Fast Global Shipping: Free delivery worldwide in 5–15 days.
• Direct from Manufacturer: Competitive pricing without compromising quality.