{"product_id":"8m0251122-service-kit-for-mercury-15hp-18hp-jlm-marine","title":"8M0251122 Service Kit for Mercury 15HP 18HP | JLM Marine","description":"\u003ch2\u003e8M0251122 Service Kit for Mercury 15HP 18HP | JLM Marine\u003c\/h2\u003e\n\n\u003cp\u003eThis comprehensive service kit is engineered for \u003cstrong\u003eMercury 15HP and 18HP outboard engines\u003c\/strong\u003e, specifically the 18HP 2-cylinder International models (serial number 0N001590 \u0026amp; Up) and 15HP Japanese models. It includes all essential components for routine maintenance—impeller, thermostat, gaskets, fuel filter, anode, and fasteners—to keep your engine running at peak performance.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eDirect Replacement for OEM Part Number:\u003c\/strong\u003e 8M0251122. This aftermarket kit delivers OEM-equivalent fit and function at a competitive price, ensuring reliable service intervals for your Mercury outboard.\u003c\/p\u003e\n\n\u003cul\u003e\n  \u003cli\u003eComplete 13-piece service kit with impeller, thermostat, fuel filter, and all necessary gaskets\u003c\/li\u003e\n  \u003cli\u003eIncludes gear oil pump and anode for comprehensive maintenance coverage\u003c\/li\u003e\n  \u003cli\u003eDesigned for Mercury 2-cylinder outboards with serial number 0N001590 and up\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\" style=\"border-collapse:collapse; width:100%;\"\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\u003e8M0251122\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\u003cdiv style=\"overflow-x:auto;\"\u003e\n  \u003ctable border=\"1\" cellpadding=\"8\" cellspacing=\"0\" style=\"border-collapse:collapse; width:100%;\"\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\u003eNotes\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\u003e2cyl International\u003c\/td\u003e\n        \u003ctd\u003e18HP\u003c\/td\u003e\n        \u003ctd\u003eSerial Number 0N001590 \u0026amp; Up\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eMercury\u003c\/td\u003e\n        \u003ctd\u003eJapanese Models\u003c\/td\u003e\n        \u003ctd\u003e15HP\u003c\/td\u003e\n        \u003ctd\u003e\u003c\/td\u003e\n      \u003c\/tr\u003e\n    \u003c\/tbody\u003e\n  \u003c\/table\u003e\n\u003c\/div\u003e\n\n\u003ch2\u003eTechnical Specifications\u003c\/h2\u003e\n\n\u003ctable border=\"1\" cellpadding=\"8\" cellspacing=\"0\" style=\"border-collapse:collapse; width:100%;\"\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\u003e8M0251122\u003c\/td\u003e\n    \u003c\/tr\u003e\n    \u003ctr\u003e\n      \u003ctd\u003eApplication\u003c\/td\u003e\n      \u003ctd\u003eMercury 15HP \u0026amp; 18HP Outboards\u003c\/td\u003e\n    \u003c\/tr\u003e\n    \u003ctr\u003e\n      \u003ctd\u003eKit Type\u003c\/td\u003e\n      \u003ctd\u003eComplete Service Kit\u003c\/td\u003e\n    \u003c\/tr\u003e\n    \u003ctr\u003e\n      \u003ctd\u003eNumber of Components\u003c\/td\u003e\n      \u003ctd\u003e13 pieces (multiple quantities included)\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 service kit includes the following components:\u003c\/p\u003e\n\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003e8M0075040\u003c\/strong\u003e – Gasket × 1\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003e803753\u003c\/strong\u003e – Guide Plate × 1\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003e803751\u003c\/strong\u003e – Insert × 1\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003e803749\u003c\/strong\u003e – Key × 1\u003c\/li\u003e\n  \u003cli\u003e\u003cspan style=\"color:red;\"\u003e\u003cstrong\u003e803748\u003c\/strong\u003e – Impeller × 1 (critical wear component)\u003c\/span\u003e\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003e823042046\u003c\/strong\u003e – Screw × 3\u003c\/li\u003e\n  \u003cli\u003e\u003cspan style=\"color:red;\"\u003e\u003cstrong\u003e804540\u003c\/strong\u003e – Thermostat × 1\u003c\/span\u003e\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003e27-853702005\u003c\/strong\u003e – Thermostat Gasket × 1\u003c\/li\u003e\n  \u003cli\u003e\u003cspan style=\"color:red;\"\u003e\u003cstrong\u003e35-8M0088825\u003c\/strong\u003e – Fuel Filter × 1\u003c\/span\u003e\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003e12-191833\u003c\/strong\u003e – Drain Screw Gasket × 3\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003e27-828816\u003c\/strong\u003e – Oil Drain Screw Gasket × 1\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003e803731\u003c\/strong\u003e – Anode × 1\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003e24OP149\u003c\/strong\u003e – Gear Oil Pump × 1\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2\u003eInstallation Guide\u003c\/h2\u003e\n\n\u003cp\u003eFollow these steps to install the service kit components. Always refer to your Mercury service manual for model-specific procedures:\u003c\/p\u003e\n\n\u003col\u003e\n  \u003cli\u003e\n\u003cstrong\u003ePreparation:\u003c\/strong\u003e Disconnect the fuel line and remove the lower unit from the engine according to your service manual. Drain all gear oil into a suitable container.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eRemove Old Impeller:\u003c\/strong\u003e Access the water pump housing and carefully extract the old impeller (803748), guide plate (803753), and insert (803751). Inspect the housing for wear or damage.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eClean Surfaces:\u003c\/strong\u003e Thoroughly clean all gasket surfaces on the pump housing and lower unit. Remove old gasket material to ensure proper sealing.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eInstall New Impeller Assembly:\u003c\/strong\u003e Lubricate the new impeller with glycerin or soapy water, then install it with the key (803749), insert, and guide plate in the correct orientation.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eReplace Thermostat:\u003c\/strong\u003e Remove the old thermostat (804540) from its housing and clean the mating surface. Install the new thermostat with a fresh gasket (27-853702005).\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eInstall Gaskets:\u003c\/strong\u003e Position the new water pump gasket (8M0075040) on the lower unit housing. Ensure proper alignment before reassembly.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eReassemble Lower Unit:\u003c\/strong\u003e Carefully reinstall the lower unit onto the engine, torquing all screws (823042046) to factory specifications.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eReplace Drain Screw Gaskets:\u003c\/strong\u003e Install new drain screw gaskets (12-191833) and oil drain screw gasket (27-828816) on all drain plugs before refilling.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eRefill Gear Oil:\u003c\/strong\u003e Use the included gear oil pump (24OP149) to refill the lower unit with Mercury Premium Gear Lube or equivalent. Fill until oil appears at the upper vent hole.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eReplace Fuel Filter:\u003c\/strong\u003e Locate the inline fuel filter and replace it with the new filter (35-8M0088825). Ensure all connections are secure and free of leaks.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eInstall Anode:\u003c\/strong\u003e Replace the old anode (803731) with the new one, ensuring proper electrical contact for corrosion protection.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eTest Run:\u003c\/strong\u003e Reconnect the fuel line, prime the system, and run the engine in a test tank or on-water. Check for proper water flow from the tell-tale and inspect for any leaks.\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 Mercury engine?\u003c\/strong\u003e\u003cbr\u003e\nA: Check your engine's serial number plate—this kit fits 18HP 2-cylinder International models with serial number 0N001590 and up, as well as 15HP Japanese models. Cross-reference your serial number with the compatibility table above or consult your Mercury dealer.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eQ: How often should I replace the impeller and service components?\u003c\/strong\u003e\u003cbr\u003e\nA: Mercury recommends replacing the water pump impeller every 2–3 years or 200–300 hours of operation, whichever comes first. The thermostat, fuel filter, and gaskets should be replaced at the same interval or if you notice overheating, poor water flow, or fuel delivery issues.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eQ: What are the signs that my impeller or thermostat has failed?\u003c\/strong\u003e\u003cbr\u003e\nA: Common symptoms include weak or no water flow from the tell-tale, engine overheating alarms, steam from the engine, or reduced cooling performance. If you notice any of these, inspect and replace the impeller and thermostat immediately to prevent engine damage.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eQ: Can I reuse the old gaskets and screws?\u003c\/strong\u003e\u003cbr\u003e\nA: No, always replace gaskets with new ones to ensure proper sealing and prevent leaks. The kit includes all necessary gaskets and screws—reusing old components can lead to water intrusion, oil leaks, and premature part failure.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eQ: What type of gear oil should I use with the included pump?\u003c\/strong\u003e\u003cbr\u003e\nA: Use Mercury Premium Gear Lube or a high-quality marine gear oil rated for outboard lower units. The included pump (24OP149) makes refilling easy and minimizes mess.\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":52418325479737,"sku":"25KM264-2N","price":68.5,"currency_code":"USD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0885\/0433\/6697\/files\/kit-25KM264-2N_e09c2dfe-14ab-45b2-8d92-06840cdc018a.png?v=1776686856","url":"https:\/\/jlmmarine.com\/es\/products\/8m0251122-service-kit-for-mercury-15hp-18hp-jlm-marine","provider":"JLM Marine Boat Parts Limited","version":"1.0","type":"link"}