Water Pump Impeller Kit for OMC Stringer 400-800 Series Stern Drives

Water Pump Impeller Kit – Fits OMC Stringer 400-800 Series Stern Drives (Replaces 983218, 18-3386)

This water pump impeller repair kit is designed for OMC Stringer 400 and 800 series stern drives (100–260 HP) manufactured from 1962–1985. It is compatible with 4-cylinder, V6, and V8 engines within this range. Note: This kit does not fit OMC Cobra models.

This kit provides a direct replacement solution for multiple OEM and aftermarket part numbers, ensuring a precise fit and reliable performance for maintaining your engine's cooling system.

• Complete Assembly: The kit includes all necessary components for a full water pump service, including the housing, impeller, wear plate, seals, and O-rings.
• Direct Installation: Designed to OEM specifications for a straightforward replacement of the original water pump assembly in OMC Stringer stern drives.
• Verified Quality: Components are produced in ISO9002 certified facilities to meet or exceed original equipment standards.

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

This JLM Marine kit includes the following components:

• "O" Rings
• Driveshaft Seal
• SS Wear Plate
• Water pump Housing
• Impeller
• Impeller Key Way

Installation Guide

1. Safety First: Before starting, disconnect the boat's battery to prevent accidental starting.
2. Access the Pump: Depending on your model, you will need to remove the stern drive unit from the transom shield to access the water pump.
3. Remove Old Pump: Unscrew the bolts holding the old water pump housing in place and carefully remove the entire assembly. Note the orientation of the parts.
4. Clean Surface: Thoroughly clean the mounting surface on the gear housing, ensuring it is free of old gasket material, sealant, and corrosion.
5. Install New Components: Place the new wear plate and gasket onto the housing. Lightly lubricate the new impeller and the inside of the new housing with soapy water or appropriate lubricant and install it with the key way.
6. Seat the Housing: Carefully slide the new housing over the impeller. The fins should bend in the correct rotational direction.
7. Secure Assembly: Install and tighten the new bolts and O-rings/seals according to your service manual's torque specifications.
8. Reassemble and Test: Reinstall the stern drive unit. Reconnect the battery, supply water to the drive, and start the engine to check for proper water flow from the tell-tale outlet and for any leaks.

Troubleshooting & FAQ

Q: How can I confirm this kit fits my OMC Stringer drive?

A: This kit is designed for all OMC Stringer drives from 1962-1985, including 400 and 800 series models. Crucially, it does NOT fit OMC Cobra models. Please check your drive model and year, and cross-reference the part numbers in our list to ensure compatibility.

Q: What are the signs that my water pump impeller needs replacement?

A: Common signs of a failing impeller include engine overheating at idle or low speeds, a weak or non-existent water stream from the "telltale" outlet, and visible cracking or damage to the old impeller's blades upon inspection.

Q: How often should the water pump impeller be replaced?

A: For preventative maintenance, it is recommended to inspect the impeller annually and replace it every 1-2 years, depending on usage (especially in saltwater or high-debris environments) and manufacturer recommendations.

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.