Water Pump Repair Kit – Fits Mercury/Mariner 9.9-15 HP 4-Stroke Outboards (Replaces 99157T2)

Water Pump Repair Kit – Fits Mercury/Mariner 9.9-15 HP 4-Stroke Outboards (Replaces 99157T2)

This comprehensive water pump repair kit is engineered for specific Mercury and Mariner outboard engines. It is designed to fit 9.9 HP 4-stroke (323cc) BigFoot models (USA-made serial numbers 0G760300-0T979999 and Belgium-assembled 0P075166-0P325499), and 15 HP BigFoot 4-stroke outboards (USA-made serial numbers 0G590000-1B727495 and Belgium-assembled 997311 and up).

As a direct replacement for multiple OEM part numbers, this kit ensures a precise fit and restores cooling system performance. It is also compatible with a range of 2-stroke Mercury/Mariner models from 15 HP to 25 HP.

• Engineered for higher flow rates and improved cooling efficiency.
• Includes all necessary components for a complete overhaul, such as the housing, impeller, gaskets, and seals.
• Direct replacement installation requires no special 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.

Technical Specifications

Package Contents

• 1 x Pump Housing Assembly (Replaces 99157A02/99157A1)
• 1 x Face Plate (Replaces 85083)
• 1 x Gasket (Replaces 993261)
• 1 x Water Pump Impeller (Replaces 8508910/47-85089-3/47-85089-10)
• 1 x Key (Replaces 8M0032838)
• 1 x Seal (Replaces 85090001/85090)
• 2 x Washer (transparent)
• 4 x Grommet
• 3 x O-ring (Replaces 69202, 35276, 86203)

Explosion Diagram

Installation Guide

1. Safety First: Disconnect the engine's battery and ensure the engine is securely mounted before starting.
2. Access the Pump: Remove the lower unit (gearcase) from the outboard's driveshaft housing. This typically involves removing several bolts.
3. Remove Old Pump: Unscrew the bolts holding the water pump housing in place and slide the entire assembly off the driveshaft.
4. Clean Surfaces: Thoroughly clean the area, removing any old gasket material or debris from the driveshaft and mating surfaces.
5. Install New Components: Slide the new gasket and face plate onto the driveshaft. Install the new impeller, making sure to orient the vanes correctly (typically clockwise when viewed from above).
6. Secure New Housing: Place the new housing over the impeller and press down while turning the driveshaft to seat the impeller. Secure it with the provided bolts and tighten to the manufacturer's torque specifications.
7. Reassemble: Reinstall the lower unit, ensuring the driveshaft, shift shaft, and water tube are properly aligned. Test the engine using a water source (flusher or test tank) to confirm proper water flow from the tell-tale outlet.

Troubleshooting & FAQ

Q: How do I confirm this kit fits my engine?
A: This kit fits specific Mercury and Mariner models. The most important step is to check your engine's serial number against the ranges listed in the compatibility table. For 9.9 HP and 15 HP BigFoot models, the serial number is the best indicator of fitment.

Q: What are the signs that my water pump is failing?
A: Common symptoms include the engine overheating, a weak or non-existent water stream from the "tell-tale" outlet, or a brittle/cracked impeller found during routine inspection. Timely replacement prevents engine damage.

Q: How often should I replace the water pump impeller?
A: For optimal performance and engine protection, it is recommended to inspect the impeller annually and replace it every 1-2 years or every 100-200 hours of use, depending on operating conditions (e.g., saltwater vs. freshwater use).

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.