Water Pump Repair Kit – Fits Mercury/Mariner 9.9–25 HP (Replaces 46-99157T2, 46-85098A2)

Water Pump Repair Kit – Fits Mercury/Mariner 9.9–25 HP (Replaces 46-99157T2, 46-85098A2)

This water pump repair kit is designed for Mercury and Mariner outboard engines, including the necessary components to service the upper water pump assembly. It is a direct replacement for specific 2-stroke and 4-stroke models ranging from 9.9 to 25 HP.

Direct Replacements: This kit replaces Mercury part numbers 46-99157T2, 46-99157A2, 46-85098A2, 85098A2, 99157A2, and 99157T2.

• Installation: Designed for the upper water pump assembly.
• Materials: Features a durable SS316 stainless steel housing, a neoprene marine rubber impeller, and non-asbestos gaskets for reliable sealing.
• Engine Compatibility: Fits select Mercury/Mariner 2-Stroke 15–25 HP (1980–1998) and 4-Stroke 9.9–15 HP (1995–2006) models.

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/Mariner 2-Stroke Models

Mercury/Mariner 4-Stroke Models

Technical Specifications

Package Contents

• 1 x Pump Housing Assembly (Replaces 99157A02, 99157A1)
• 1 x Impeller (Replaces 8508910, 47-85089-3, 47-85089-10)
• 1 x Face Plate (Replaces 85083)
• 1 x Gasket (Replaces 993261)
• 1 x Key (Replaces 8M0032838)
• 1 x Seal (Replaces 85090001, 85090)
• 2 x Washer (transparent) (Replaces 12-86645-1)
• 4 x Insulator (Replaces 23-85095)
• 3 x O-ring
• 1 x Water Tube Guide Sleeve

Installation Guide

1. Safety First: Disconnect the negative battery terminal and ensure the engine cannot start accidentally.
2. Detach Lower Unit: Remove the bolts securing the lower unit (gearcase) to the upper leg of the outboard. Note the location of bolts of different lengths.
3. Disconnect Linkages: Disconnect the shift linkage. You may need to shift the engine into forward gear to access it.
4. Remove Lower Unit: Carefully lower and remove the gearcase from the engine.
5. Access Water Pump: With the lower unit removed, locate and unbolt the water pump housing.
6. Disassemble Pump: Remove the old housing, impeller, wear plate, gaskets, and seals. Pay close attention to the order and orientation of each part.
7. Clean Surfaces: Thoroughly clean the mounting surfaces on the gearcase, removing any old gasket material or corrosion.
8. Install New Components: Install the new gaskets, wear plate, key, and impeller. When installing the impeller, turn the driveshaft clockwise to seat the vanes correctly inside the housing.
9. Install New Housing: Place the new housing over the impeller and tighten the bolts to the manufacturer's specified torque.
10. Reassemble: Reinstall the lower unit, ensuring the water tube, driveshaft splines, and shift shaft are correctly aligned. Reconnect the shift linkage.
11. Final Checks: Secure all bolts, reconnect the battery, and test the engine using a water supply (flushing muffs or in water). Check for strong water flow from the tell-tale outlet.

Troubleshooting & FAQ

How do I confirm this fits my engine?

The best way is to compare your engine's model, horsepower, and serial number against the compatibility tables on this page. For many Mercury/Mariner engines, the serial number is critical for identifying the correct parts. If you are unsure, use the provided serial number guide or contact our support team with your engine details.

What are the signs of a failing water pump?

Common signs include the engine temperature alarm sounding, a weak or non-existent water stream from the "tell-tale" port, or steam from the exhaust. During a visual inspection, a worn impeller will appear cracked, brittle, or have fins that are permanently bent or broken.

How often should a water pump impeller be replaced?

As a crucial preventative maintenance item, we recommend inspecting the impeller annually and replacing it every 1-2 years or 100-200 hours of use, whichever comes first. This interval should be shortened if the engine is operated frequently in sandy, silty, or saltwater conditions.

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.