8M0090558 Maintenance Kit for Mercury 40-60 EFI 4 Cylinder | JLM Marine

8M0090558 Maintenance Kit for Mercury 40-60 EFI 4 Cylinder

This comprehensive maintenance kit is specifically designed for Mercury 40-60 EFI 4 Cylinder outboard engines. It provides all the essential components needed for routine servicing, ensuring your engine runs at peak performance and reliability.

This kit serves as a direct replacement for OEM part number 8M0090558, delivering quality components that meet or exceed original equipment specifications.

• Complete maintenance solution with filters, thermostat, gaskets, and gear oil pump
• Includes all critical wear items for comprehensive engine service
• Designed specifically for Mercury EFI 4-cylinder powerheads

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 maintenance kit includes the following components:

• 8M0117413 (Thermostat) x1
• 824853 (Gasket) x1
• 35-879884T (Fuel filter) x1 View Part →
• 35-8M0153652 (Fuel filter) x1 View Part →
• 35-8M0162829 (Oil filter) x1 View Part →
• 8M007119 (Drain Gasket) x1
• 830749 (Drain Gasket) x3
• 24OP149 (Gear Oil Pump) x1

Installation Guide

1. Ensure the engine is off and cool before beginning any maintenance work. Gather all tools and components from the kit.
2. Locate and remove the old oil filter using an appropriate filter wrench. Install the new oil filter (35-8M0162829) hand-tight, adding a thin film of oil to the gasket.
3. Drain the engine oil and remove the drain plug. Replace the drain gasket (8M007119) with a new one from the kit before reinstalling the plug.
4. Access the thermostat housing and remove the old thermostat. Install the new thermostat (8M0117413) with the included gasket (824853), ensuring proper orientation.
5. Locate the fuel filter assembly and disconnect fuel lines carefully. Replace both fuel filters (35-879884T and 35-8M0153652) according to their respective positions.
6. Drain the lower unit gear oil by removing both drain and fill plugs. Inspect the old oil for metal particles or water contamination.
7. Use the gear oil pump (24OP149) to refill the lower unit from the bottom drain hole until oil appears at the top fill hole. Install drain gaskets (830749) on both plugs.
8. Double-check all filter installations, gasket seals, and plug torque specifications. Refill engine oil to the proper level per manufacturer specifications.
9. Start the engine and allow it to reach operating temperature. Check for leaks around all serviced components.
10. Shut down the engine and recheck fluid levels after it has cooled. Top off oil if necessary.
11. Inspect the work area and ensure all old parts are disposed of properly. Record the maintenance date and engine hours in your service log.
12. Test run the engine under normal operating conditions and monitor performance. Address any unusual sounds or leaks immediately.

Troubleshooting & FAQ

Q: How do I confirm this maintenance kit fits my Mercury engine?
A: This kit is designed specifically for Mercury 40-60 HP EFI 4-cylinder engines. Verify your engine model using the serial number guide linked above, or check your engine's specifications plate to confirm compatibility before ordering.

Q: How often should I perform maintenance using this kit?
A: Mercury recommends performing routine maintenance every 100 hours of operation or annually, whichever comes first. In harsh operating conditions (saltwater, heavy use), more frequent service intervals may be necessary.

Q: Can I install this kit myself or do I need a professional?
A: While experienced mechanics can perform this maintenance, professional installation is recommended to ensure proper procedure, torque specifications, and warranty protection, especially if you're unfamiliar with outboard service.

Q: What are the signs that I need to replace these maintenance items?
A: Common indicators include poor fuel economy, rough idling, overheating, difficulty shifting gears, milky gear oil (water contamination), or decreased engine performance. Regular preventive maintenance prevents these issues.

Q: Does this kit include engine oil and gear oil fluids?
A: No, this kit includes filters, gaskets, thermostat, and a gear oil pump for refilling, but does not include the actual engine oil or gear oil fluids. You will need to purchase appropriate Mercury-spec lubricants separately.

Q: Is this an OEM part or 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.