8M0251129 Annual Service Kit for Mercury 70HP 75HP 80HP 90HP 115HP 125HP 60HP | JLM Marine

Annual Service Kit for Mercury 70HP 75HP 80HP 90HP 115HP 125HP 60HP – OEM 8M0251129

This comprehensive annual service kit is designed for Mercury outboard engines ranging from 60HP to 125HP. It includes all essential maintenance components needed for a complete yearly service, ensuring your engine runs smoothly and reliably season after season.

This kit directly replaces OEM part number 8M0251129 and provides everything required for routine maintenance, including impeller, seals, gaskets, thermostat, fuel filter, and drain components.

• Complete 17-piece service kit with impeller, thermostat, fuel filter, and all necessary seals and gaskets
• Fits Mercury 60HP Bigfoot, 70-90HP (1987-2016), and 115-125HP carbureted models (1987-2005)
• Includes gear oil pump for convenient fluid changes during service

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

This annual service kit includes the following components:

• 47-43026Q02 (Impeller) x 1
• 26-8M2014338 (Seal) x 1
• 2210 (Seal) x 1
• 8172761 (Plate) x 1
• 25-21836 (O-ring) x 2
• 27-8M0142616 (Gasket) x 1
• 27-8172771 (Gasket) x 1
• 28-8M0032833 (Key) x 1
• 26-45577 (Seal) x 1
• 25-90196 (O-ring) x 1
• 26-830749 (Gasket) x 3
• 803061T1 (Thermostat) x 1
• 35-877565T1 (Fuel Filter) x 1
• 8M007119 (Drain Gasket) x 1
• 830749 (Drain Gasket) x 3
• 24OP149 (Gear Oil Pump) x 1

Installation Guide

1. Ensure the engine is off and cool before beginning any maintenance work. Disconnect the battery and fuel line for safety.
2. Remove the lower unit from the engine following your Mercury service manual procedures. Place the unit on a clean work surface.
3. Remove the old water pump housing and impeller assembly. Inspect the housing for wear or damage.
4. Install the new impeller (47-43026Q02) with a light coating of marine grease, ensuring the blades face the correct direction. Install the new plate (8172761) and key (28-8M0032833).
5. Replace all seals (26-8M2014338, 2210, 26-45577) and O-rings (25-21836, 25-90196) in their respective positions. Ensure proper seating to prevent leaks.
6. Install new gaskets (27-8M0142616, 27-8172771, 26-830749) on the water pump housing and reassemble the pump assembly.
7. Drain the lower unit gear oil completely and inspect for contaminants. Use the included gear oil pump (24OP149) to refill with fresh Mercury gear lube to the proper level.
8. Install new drain gaskets (8M007119, 830749) on all drain and fill plugs. Tighten plugs to manufacturer specifications.
9. Replace the thermostat (803061T1) in the powerhead, ensuring the temperature rating matches your engine requirements. Install with a new gasket.
10. Install the new fuel filter (35-877565T1) in the fuel system, ensuring proper flow direction. Check all fuel line connections for security.
11. Reattach the lower unit to the engine, torquing all fasteners to factory specifications. Reconnect the fuel line and battery.
12. Start the engine and check for proper water flow from the tell-tale. Inspect all service points for leaks and proper operation.

Troubleshooting & FAQ

Q: How do I confirm this kit fits my specific Mercury engine?
A: Cross-reference your engine's HP rating and year with the compatibility table above. For 60HP Bigfoot models, verify your serial number falls within the range 0G590000 to 0T979999. If you have a 115-125HP engine, confirm it's a carbureted model (not EFI) from 1987-2005.

Q: How often should I perform this annual service?
A: Mercury recommends performing this comprehensive service every 100 hours of operation or once per year, whichever comes first. If you operate in saltwater, sandy conditions, or use your engine heavily, consider servicing more frequently.

Q: What are the signs that my impeller needs replacement?
A: Common symptoms include weak water flow from the tell-tale, engine overheating, steam from the engine, or visible damage to impeller blades during inspection. If your engine is running hot or water flow is reduced, replace the impeller immediately to prevent damage.

Q: Can I use this kit on EFI (fuel-injected) Mercury engines?
A: This kit is designed for carbureted models only. For 115-125HP engines, verify your model has a carburetor system rather than electronic fuel injection before ordering.

Q: Do I need any special tools to install this service kit?
A: Basic marine mechanic tools are required, including socket sets, torque wrench, gasket scraper, and marine grease. The included gear oil pump (24OP149) simplifies lower unit servicing. Refer to your Mercury service manual for specific torque specifications and procedures.

Q: What's the difference between OEM and aftermarket service kits?
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.