Water Pump Impeller Kit with Housing – Fits Mercury Marine/MerCruiser 30-250 HP (Replaces 817275A5, 817275Q05)

Water Pump Impeller Kit with Housing – Fits Mercury Marine/MerCruiser 30-250 HP (Replaces 817275A5, 817275Q05)

This complete water pump impeller repair kit includes the housing and all necessary seals, gaskets, and hardware for a direct replacement. It is designed to restore cooling system performance on a wide range of Mercury, MerCruiser, and Force outboard and sterndrive engines.

This assembly is a direct replacement for Mercury part numbers 817275A5, 817275A6, 817275A4, 817275T4, 817275Q4, and 817275Q05. It also replaces aftermarket parts from Sierra (18-3570, 18-3147), Mallory (9-48315, 9-48314), GLM (12415), and Redline (RL3570).

• Fits Mercury/MerCruiser (30-250 HP) and Chrysler/Force (75-120 HP) models.
• Includes a durable neoprene impeller, stainless steel housing, and non-asbestos gaskets.
• Engineered as a direct, ready-to-install replacement for the original OEM assembly.

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. For Mercury owners, here’s a guide to help you identify your engine’s serial/model: Mercury Serial Number Guide. You can also review exploded diagrams to verify part numbers: Mercury Parts Diagrams & Catalog.

Technical Specifications

Package Contents

• 1 x Carrier Seal (821759A4)
• 1 x Impeller (47-43026T2)
• 1 x Impeller Plate (8172761)
• 1 x Impeller Key (28-43037)
• 2 x O-Ring (25-21836)
• 1 x Seal Ring Gasket (26-45577B1)
• 1 x Face Seal and Tool (26-816575A2)
• 1 x Impeller Gasket (27-430331)
• 1 x Impeller Gasket (27-8172771)
• 1 x Drain Screw Gasket (12-191833)

Installation Guide

1. Safety First: Disconnect the engine's battery before starting work.
2. Remove Lower Unit: Unbolt and carefully detach the lower unit (gearcase) from the outboard leg or sterndrive.
3. Access Pump: Locate the water pump assembly on top of the lower unit and remove the bolts securing its housing.
4. Disassemble: Lift off the old housing. Remove the impeller, wear plate, gaskets, and seals, taking note of the original orientation of the impeller vanes.
5. Clean Surfaces: Thoroughly clean all mating surfaces to remove any old gasket residue, corrosion, or debris. A clean surface is critical for a good seal.
6. Install New Components: Place the new wear plate and gaskets. Slide the new impeller key onto the driveshaft.
7. Seat Impeller: Lubricate the inside of the new housing and slide the new impeller onto the driveshaft, turning the shaft clockwise to correctly bend the vanes.
8. Secure Housing: Lower the new housing over the impeller, align the bolt holes, and tighten the bolts to the manufacturer's specified torque.
9. Reassemble: Reinstall the lower unit to the engine.
10. Test: Reconnect the battery. Start the engine in a water supply (using flushing muffs or in the water) and confirm a steady stream of water from the tell-tale outlet.

Troubleshooting & FAQ

How do I confirm this kit fits my specific engine?
The most reliable method is to match your engine's model, year, and serial number against our compatibility table. For Mercury owners, use the linked serial number guide to verify your details. If your engine is listed, this kit is a direct replacement for the specified OEM part numbers.

What are the signs of a failing water pump impeller?
Common signs include a weak or non-existent water stream from the "tell-tale" outlet, engine overheating alarms, and reduced engine performance. A visual inspection may also reveal cracked, stiff, or broken impeller vanes.

How often should I replace the water pump impeller?
As a general maintenance rule, it is recommended to inspect your impeller annually and replace it every 1-2 years, or every 100-200 hours of use, depending on operating conditions. More frequent replacement may be needed if you operate in sandy, silty, or saltwater environments.

OEM vs. Aftermarket?
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.

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

What is your warranty and return policy?
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.