Water Pump Repair Kit – Fits Mercury & Mariner 2-Stroke 15-25 HP & 4-Stroke 9.9-15 HP (Replaces 99157T2, 85098A2, 99157A2)

Water Pump Repair Kit – Fits Mercury & Mariner 2-Stroke 15-25 HP & 4-Stroke 9.9-15 HP (Replaces 99157T2, 85098A2, 99157A2)

This upper water pump repair kit is designed for a range of Mercury & Mariner 2-Stroke 15–25 HP (1980–1998) and 4-Stroke Bigfoot 9.9–15 HP (1998) outboard motors. It serves as a comprehensive solution for replacing worn or damaged water pump components to restore cooling system performance.

This kit directly replaces Mercury OEM part numbers 46-99157T2, 46-99157A2, and 46-85098A2. It is also a compatible replacement for aftermarket parts including Marinepro 99157T2, GHmarine 99157T2, and UanofCn 99157T2.

• Complete Kit: Includes a new neoprene impeller, stainless steel housing, face plate, gaskets, seals, and O-rings for a full service.
• Durable Materials: Features a corrosion-resistant Stainless Steel 316 housing and a high-performance neoprene impeller for longevity.
• Direct Fitment: Engineered as an OEM direct fit replacement, ensuring proper installation without modifications.

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.

Mercury Outboards

Mariner Outboards

Force Outboards

Sears Outboards

Technical Specifications

Package Contents

• 1 x Housing, Pump Assembly (Replaces 99157A02 / 99157A1)
• 1 x Face Plate (Replaces 85083)
• 1 x Gasket (Replaces 993261)
• 1 x Impeller (Replaces 47-85089 / 8M0024502 / 8508910)
• 1 x Key (Replaces 8M0032838)
• 1 x Seal (Replaces 85090001 / 85090)
• 1 x Water Tube Guide Sleeve
• 2 x Washer, transparent (Replaces 12-86645-1)
• 2 x Gear Lube Fill and Vent Screw O-rings
• 3 x O-ring
• 4 x Insulator (Replaces 23-85095)

Installation Guide

Professional installation is recommended. Always consult your service manual for detailed instructions specific to your engine model.

1. Safety First: Disconnect the battery and disable the ignition system.
2. Access the Lower Unit: Shift the outboard into neutral. Remove the bolts securing the lower unit (gearcase) to the upper driveshaft housing. Carefully lower and separate the unit.
3. Remove Old Pump: Unscrew the bolts on the top of the water pump housing. Slide the housing off the driveshaft to expose the impeller. Note the rotational direction of the old impeller vanes.
4. Disassemble Pump: Remove the old impeller, face plate, gaskets, and key from the driveshaft.
5. Clean Surfaces: Thoroughly clean the mounting surfaces on the gearcase and the inside of the housing area. Remove any old gasket material or debris.
6. Install New Components: Place the new gasket and face plate onto the gearcase. Install the new key into the driveshaft keyway.
7. Install New Impeller: Lightly lubricate the pump housing interior. Slide the new impeller onto the driveshaft while turning the shaft clockwise to correctly orient the vanes.
8. Install New Housing: Place the new gaskets and seals on the housing as required. Carefully slide the housing down over the impeller.
9. Reassemble Pump: Secure the new housing with its bolts, tightening them to the manufacturer's specified torque.
10. Reattach Lower Unit: Guide the lower unit back into position, ensuring the driveshaft, shift shaft, and water tube align correctly. Reinstall and tighten the mounting bolts.
11. Test Operation: Reconnect the battery. Start the engine using a water supply (flushing muffs or in water) and confirm a steady stream of water from the tell-tale outlet.

Troubleshooting & FAQ

Q: How do I confirm this kit fits my exact engine?
A: The best method is to cross-reference your engine's part number with the numbers listed in our "Part Number Cross-Reference" table. Additionally, carefully review the "Compatible Engine Models" section and compare the specifications (HP, year, serial number range) with your outboard.

Q: What are the common signs of a failing water pump?
A: The most common indicators include a weak or non-existent water stream from the "tell-tale" outlet, an engine overheating alarm, or a noticeable decrease in engine performance. We recommend inspecting your impeller annually.

Q: How often should I replace my water pump impeller?
A: As a general rule of thumb, it is recommended to replace your water pump impeller every 1 to 2 years or every 100-200 hours of operation, whichever comes first. This interval can vary based on usage conditions (e.g., saltwater vs. freshwater).

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.