8M0090558 Service Kit for Mercury 40HP 50HP 60HP EFI | JLM Marine

8M0090558 Service Kit for Mercury 40HP 50HP 60HP EFI

This comprehensive service kit is specifically designed for Mercury 40HP, 50HP, and 60HP EFI outboard engines. It provides all the essential maintenance components needed for a complete routine service, ensuring your engine runs at peak performance and reliability.

This kit directly replaces OEM part number 8M0090558, offering a cost-effective solution for scheduled maintenance without compromising on quality or fit.

• Complete service kit with oil filter, fuel filters, thermostat, gaskets, and gear oil pump
• Designed for Mercury EFI (Electronic Fuel Injection) outboards
• Includes all critical maintenance components in one convenient package

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 service kit includes the following components:

• 8M0162829 - Oil Filter × 1
• 879884T - Fuel Filter × 1
• 8M0153652 - Fuel Filter × 1
• 8M0117413 - Thermostat × 1
• 824853.0 - Thermostat Gasket × 1
• 8M0007119 - Oil Plug Drain Gasket × 1
• 830749.0 - Lower Unit Drain Gasket × 3
• 24OP149 - Gear Oil Pump × 1

Installation Guide

1. Preparation: Ensure the engine is cool and the outboard is in a stable, upright position. Gather all necessary tools including wrenches, drain pan, and the gear oil pump included in this kit.
2. Oil Change: Remove the oil drain plug using the new drain gasket and drain old engine oil into a suitable container. Replace the old oil filter with the new one, applying a thin coat of oil to the gasket before installation.
3. Fuel Filter Replacement: Locate and remove the old fuel filters. Install the new fuel filters ensuring proper orientation and secure connections to prevent leaks.
4. Thermostat Service: Remove the thermostat housing cover and extract the old thermostat. Install the new thermostat with fresh gaskets ensuring correct orientation for proper coolant flow.
5. Lower Unit Service: Remove all three lower unit drain and fill plugs, allowing old gear oil to drain completely. Inspect the oil for metal shavings or water contamination.
6. Lower Unit Refill: Using the included gear oil pump and new drain gaskets, pump fresh gear oil into the lower fill hole until it emerges from the top vent hole. Replace plugs starting with the top vent first, then the lower drain/fill plug.
7. System Check: Refill engine oil to the proper level per your owner's manual specifications. Start the engine and check for any leaks around filter and gasket areas.
8. Final Inspection: Allow the engine to reach operating temperature and verify proper thermostat operation by monitoring coolant flow. Recheck all drain plugs and filters for secure installation and no leakage.

Troubleshooting & FAQ

Q: How do I confirm this service kit fits my Mercury outboard?
A: This kit is designed specifically for Mercury 40HP, 50HP, and 60HP EFI models. Verify your engine's horsepower rating and confirm it has electronic fuel injection (EFI). You can cross-reference the OEM part number 8M0090558 in your owner's manual.

Q: How often should I perform this service on my Mercury EFI outboard?
A: Mercury recommends a complete service every 100 hours of operation or annually, whichever comes first. In harsh conditions, consider more frequent intervals to maintain optimal engine performance and longevity.

Q: Can I use individual replacement parts instead of purchasing the entire kit?
A: Yes, individual components are available separately; however, this complete service kit offers better value and ensures you have all necessary maintenance items on hand.

Q: What are signs that my fuel filters or thermostat need replacement?
A: Fuel filter issues often manifest as rough idling, hesitation under acceleration, or difficulty starting. Thermostat problems typically cause overheating, prolonged warm-up times, or inconsistent operating temperatures.

Q: Is the gear oil pump reusable for future lower unit services?
A: Yes, the included gear oil pump is a durable tool designed for multiple uses. Clean it thoroughly after each use and store it properly.

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.

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.

Q: What is your warranty and return policy?
A: This product includes a 1-year warranty against manufacturing defects under normal use. Returns are accepted within our standard return window.

Important Notes

• Verify that the product images and specifications match your original part.
• 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.