{"product_id":"8m0090559-maintenance-kit-for-mercury-40hp-50hp-60hp-efi-4-stroke-bigfoot-ct-jlm-marine","title":"8M0090559 Maintenance Kit for Mercury 40HP 50HP 60HP EFI 4-Stroke BigFoot CT | JLM Marine","description":"\u003ch2\u003e8M0090559 Maintenance Kit for Mercury 40HP 50HP 60HP EFI 4-Stroke BigFoot CT\u003c\/h2\u003e\n\n\u003cp\u003eThis comprehensive maintenance kit is specifically designed for \u003cstrong\u003eMercury 40HP, 50HP, and 60HP EFI 4-Cylinder 4-Stroke outboard motors\u003c\/strong\u003e equipped with \u003cstrong\u003eBigFoot and CT gearcases\u003c\/strong\u003e. It consolidates all essential service components into one package, ensuring your engine receives complete care during routine maintenance intervals.\u003c\/p\u003e\n\n\u003cp\u003eThis kit directly replaces Mercury OEM maintenance kit \u003cstrong\u003e8M0090559\u003c\/strong\u003e, providing a complete solution for water pump repair, cooling system service, and filtration replacement in a single purchase.\u003c\/p\u003e\n\n\u003cul\u003e\n\u003cli\u003eIncludes water pump repair kit, thermostat assembly, fuel filters (both high and low pressure), oil filter, and drain gaskets\u003c\/li\u003e\n\u003cli\u003eDesigned specifically for EFI 4-cylinder models with BigFoot and CT gearcase configurations\u003c\/li\u003e\n\u003cli\u003eStreamlines maintenance by bundling all critical service components together\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2\u003ePart Number Cross-Reference\u003c\/h2\u003e\n\n\u003cp\u003eUse this table to confirm equivalent part numbers across OEM and aftermarket brands.\u003c\/p\u003e\n\n\u003ctable border=\"1\" cellpadding=\"8\" cellspacing=\"0\"\u003e\n\u003cthead\u003e\n\u003ctr\u003e\n\u003cth\u003eBrand\u003c\/th\u003e\n\u003cth\u003ePart Number\u003c\/th\u003e\n\u003c\/tr\u003e\n\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eMercury\u003c\/td\u003e\n\u003ctd\u003e8M0090559\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\n\u003ch2\u003eCompatible Engine Models\u003c\/h2\u003e\n\n\u003cp\u003eConfirm your engine model\/year in the table below. For Mercury owners, here's a guide to help you identify your engine's serial\/model: \u003ca href=\"https:\/\/jlmmarine.com\/blogs\/serial-number-guide\/mercury-outboard-serial-number-guide\" rel=\"nofollow noopener\" target=\"_blank\"\u003eMercury Serial Number Guide\u003c\/a\u003e. You can also review exploded diagrams to verify part numbers: \u003ca href=\"https:\/\/jlmmarine.com\/blogs\/diagrams\/mercury-parts-catalog\" rel=\"nofollow noopener\" target=\"_blank\"\u003eMercury Parts Diagrams \u0026amp; Catalog\u003c\/a\u003e.\u003c\/p\u003e\n\n\u003ctable border=\"1\" cellpadding=\"8\" cellspacing=\"0\"\u003e\n\u003cthead\u003e\n\u003ctr\u003e\n\u003cth\u003eBrand\u003c\/th\u003e\n\u003cth\u003eModel\u003c\/th\u003e\n\u003cth\u003eRated HP\u003c\/th\u003e\n\u003cth\u003eStroke\u003c\/th\u003e\n\u003cth\u003eNotes\u003c\/th\u003e\n\u003c\/tr\u003e\n\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eMercury Quicksilver\u003c\/td\u003e\n\u003ctd\u003e40-50-60 EFI 4Cyl\u003c\/td\u003e\n\u003ctd\u003e40HP \/ 50HP \/ 60HP\u003c\/td\u003e\n\u003ctd\u003e4-Stroke\u003c\/td\u003e\n\u003ctd\u003e\u003cstrong\u003eBigFoot and CT gearcases only\u003c\/strong\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\n\u003ch2\u003eTechnical Specifications\u003c\/h2\u003e\n\n\u003ctable border=\"1\" cellpadding=\"8\" cellspacing=\"0\"\u003e\n\u003cthead\u003e\n\u003ctr\u003e\n\u003cth\u003eSpecification\u003c\/th\u003e\n\u003cth\u003eValue\u003c\/th\u003e\n\u003c\/tr\u003e\n\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eOEM Part Number\u003c\/td\u003e\n\u003ctd\u003e8M0090559\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eApplication\u003c\/td\u003e\n\u003ctd\u003eMercury 40HP, 50HP, 60HP EFI 4-Cylinder 4-Stroke (BigFoot \u0026amp; CT gearcases only)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eKit Type\u003c\/td\u003e\n\u003ctd\u003eComplete Maintenance Service Kit\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\n\u003ch2\u003ePackage Contents\u003c\/h2\u003e\n\n\u003cp\u003eThis maintenance kit includes the following components:\u003c\/p\u003e\n\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003e1 × Water Pump Repair Kit\u003c\/strong\u003e (47-8M0100527)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e1 × Cotter Pin\u003c\/strong\u003e (951403-0310)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e1 × Thermostat\u003c\/strong\u003e (8M0168892)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e1 × Thermostat Gasket\u003c\/strong\u003e (27-887978 \u0026amp; 27-8M0177107)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e1 × Fuel Filter Assembly\u003c\/strong\u003e (low pressure) (35-879884T)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e1 × Fuel Filter\u003c\/strong\u003e (high pressure) (35-8M0153652)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e1 × Oil Filter\u003c\/strong\u003e (35-8M0162829)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e1+3 Drain Gaskets\u003c\/strong\u003e (26-8M0007119 \u0026amp; 26-8M0204693)\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003e\u003cspan style=\"color:red;\"\u003e\u003cstrong\u003eImportant:\u003c\/strong\u003e This kit is designed exclusively for BigFoot and CT gearcase models. Verify your gearcase type before ordering.\u003c\/span\u003e\u003c\/p\u003e\n\n\u003ch2\u003eInstallation Guide\u003c\/h2\u003e\n\n\u003col\u003e\n\u003cli\u003e\n\u003cstrong\u003ePreparation:\u003c\/strong\u003e Gather necessary tools including socket set, screwdrivers, torque wrench, and drain pan. Ensure the engine is cool and in an upright position.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOil Filter Replacement:\u003c\/strong\u003e Locate the oil filter on the engine block, remove the old filter, and install the new oil filter from the kit. Tighten securely by hand.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDrain Plug Service:\u003c\/strong\u003e Remove the engine oil drain plug and gearcase drain\/fill plugs. Replace drain plug gaskets with the new gaskets provided in the kit.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFuel Filter Replacement:\u003c\/strong\u003e Replace both the low-pressure fuel filter assembly and high-pressure fuel filter. Ensure fuel line connections are secure and free from leaks.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWater Pump Service:\u003c\/strong\u003e Remove the lower unit to access the water pump housing. Disassemble the old water pump components.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWater Pump Installation:\u003c\/strong\u003e Install the new impeller, gaskets, seals, and O-rings from the water pump repair kit following the proper orientation. Lubricate components with glycerin or soapy water.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eThermostat Replacement:\u003c\/strong\u003e Locate the thermostat housing on the cylinder head and remove the cover. Replace the old thermostat and gasket with the new components from the kit.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eReassembly:\u003c\/strong\u003e Reinstall the lower unit, ensuring all bolts are torqued to manufacturer specifications. Reconnect all fuel lines and verify proper routing.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFluid Refill:\u003c\/strong\u003e Refill engine oil and gearcase lubricant to the proper levels using manufacturer-recommended fluids. Check for leaks around all service points.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSystem Check:\u003c\/strong\u003e Start the engine and verify water pump discharge (telltale stream). Check for fuel leaks, oil leaks, and proper operating temperature.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eTest Run:\u003c\/strong\u003e Run the engine at idle and then at varying RPMs to ensure all systems operate correctly. Monitor temperature gauge and watch for any abnormal sounds or leaks.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFinal Inspection:\u003c\/strong\u003e After the test run, recheck all fluid levels and inspect all service areas for leaks. Dispose of used oil, filters, and fluids properly.\u003c\/li\u003e\n\u003c\/ol\u003e\n\n\u003ch2\u003eTroubleshooting \u0026amp; FAQ\u003c\/h2\u003e\n\n\u003cp\u003e\u003cstrong\u003eQ: How do I confirm this kit fits my specific Mercury outboard?\u003c\/strong\u003e\u003cbr\u003e\nA: Verify that your engine is a 40HP, 50HP, or 60HP EFI 4-cylinder 4-stroke model equipped with either a BigFoot or CT gearcase. Standard gearcase models require a different maintenance kit. Check your engine's serial number plate or consult your owner's manual to confirm the gearcase type.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eQ: How often should I perform this maintenance service?\u003c\/strong\u003e\u003cbr\u003e\nA: Mercury recommends performing comprehensive maintenance every 100 hours of operation or annually, whichever comes first. In harsh conditions (saltwater, heavy use, extreme temperatures), consider more frequent intervals—every 50-75 hours.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eQ: Can I install just some components from this kit or do I need to use everything at once?\u003c\/strong\u003e\u003cbr\u003e\nA: While the kit is designed for complete service intervals, individual components can be replaced as needed. However, performing all maintenance tasks together ensures optimal engine performance and simplifies service scheduling.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eQ: What are the signs that my water pump or thermostat needs replacement?\u003c\/strong\u003e\u003cbr\u003e\nA: Common symptoms include weak or absent telltale stream, engine overheating, steam from the engine cover, reduced performance, or temperature alarms. If you notice any of these signs, inspect and replace the water pump and thermostat immediately.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eQ: Does this kit include engine oil and gearcase lubricant?\u003c\/strong\u003e\u003cbr\u003e\nA: No, this kit includes the oil filter and drain gaskets but does not include the actual engine oil or gearcase lubricant. Purchase the appropriate Mercury-recommended fluids separately based on your operating conditions.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eQ: Is this an OEM or aftermarket part?\u003c\/strong\u003e\u003cbr\u003e\nA: 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.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eQ: How fast do you ship and how much does it cost?\u003c\/strong\u003e\u003cbr\u003e\nA: 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.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eQ: What is your warranty and return policy?\u003c\/strong\u003e\u003cbr\u003e\nA: 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 \u0026amp; in original condition); please see our policy page or reach out for instructions.\u003c\/p\u003e\n\n\u003ch2\u003eImportant Notes\u003c\/h2\u003e\n\n\u003cul\u003e\n\u003cli\u003eVerify 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.\u003c\/li\u003e\n\u003cli\u003eThis product is an aftermarket replacement part and is not an OEM component.\u003c\/li\u003e\n\u003cli\u003eProfessional installation is recommended to ensure safety and optimal performance.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2\u003eWhy Choose JLM MARINE?\u003c\/h2\u003e\n\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eQuality Assured:\u003c\/strong\u003e As a trusted manufacturer for over 20 years, we supply top marine brands globally.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFast Global Shipping:\u003c\/strong\u003e Free delivery worldwide in 5–15 days.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDirect from Manufacturer:\u003c\/strong\u003e Competitive pricing without compromising quality.\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"JLM Marine","offers":[{"title":"Default Title","offer_id":51981001687353,"sku":"23KM778","price":74.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0885\/0433\/6697\/files\/10_5dd9e437-a14b-4788-9650-f915695af701.png?v=1772414245","url":"https:\/\/jlmmarine.com\/es\/products\/8m0090559-maintenance-kit-for-mercury-40hp-50hp-60hp-efi-4-stroke-bigfoot-ct-jlm-marine","provider":"JLM Marine Boat Parts Limited","version":"1.0","type":"link"}