{"title":"Yanmar 4-Stroke 18-30HP Marine Engine Parts","description":"\u003csection id=\"hero\" style=\"padding:16px;border:1px solid #e5e7eb;border-radius:8px;max-width:1000px;\"\u003e\n  \u003cp\u003eThis page is dedicated to Yanmar 4‑Stroke 18–30 HP marine engines and helps you find compatible parts and practical service information. Below you’ll find maintenance tips, frequently used replacement parts, and troubleshooting guidance. You can also browse the main Yanmar collection for a wider selection. Scroll to the bottom of this page to start browsing parts for this engine, and use the Filter \u0026amp; Sort controls on the collection page to narrow results by horsepower, year range, and part category.\u003c\/p\u003e\n  \u003cp\u003e\n    \u003ca href=\"https:\/\/seasierra.com\/collections\/yanmar\" style=\"display:inline-block;padding:10px 14px;background:#0d6efd;color:#fff;text-decoration:none;border-radius:6px;\"\u003eBrowse All Yanmar Parts\u003c\/a\u003e\n  \u003c\/p\u003e\n\u003c\/section\u003e\n\n\u003csection id=\"identify-model\" style=\"padding:16px;max-width:1000px;\"\u003e\n  \u003ch2\u003eHow to Identify Your 18–30 HP Model\u003c\/h2\u003e\n  \u003cul\u003e\n    \u003cli\u003eLocate the engine nameplate: typically on the starboard side of the block near the injection pump, or on the top\/front of the engine. The gearbox often has a separate ID plate.\u003c\/li\u003e\n    \u003cli\u003eRead the full model code (e.g., 2GM20, 3GM30, 2YM15, 3YM20, 3YM30). Suffixes can indicate cooling type (raw water vs. freshwater\/heat‑exchanger), regional emissions version, or gearbox ratio.\u003c\/li\u003e\n    \u003cli\u003eDistinguish platforms: older GM‑series vs. newer YM‑series small inline‑2\/inline‑3 diesels. Many routine items are platform‑specific.\u003c\/li\u003e\n    \u003cli\u003eRecord the engine serial number and gearbox model\/ratio; both help confirm exact parts compatibility.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\u003c\/section\u003e\n\n\u003csection id=\"engine-overview\" style=\"padding:16px;max-width:1000px;\"\u003e\n  \u003ch2\u003eEngine Platform Overview\u003c\/h2\u003e\n  \u003ch3\u003eYanmar GM Series (e.g., 2GM20, 3GM30)\u003c\/h3\u003e\n  \u003ctable style=\"width:100%;border-collapse:collapse;\"\u003e\n    \u003cthead\u003e\n      \u003ctr\u003e\n        \u003cth style=\"text-align:left;border-bottom:1px solid #e5e7eb;\"\u003eFeature\u003c\/th\u003e\n        \u003cth style=\"text-align:left;border-bottom:1px solid #e5e7eb;\"\u003eDescription\u003c\/th\u003e\n      \u003c\/tr\u003e\n    \u003c\/thead\u003e\n    \u003ctbody\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:6px 0;\"\u003eConfiguration\u003c\/td\u003e\n        \u003ctd style=\"padding:6px 0;\"\u003eInline 2 or 3‑cylinder, naturally aspirated 4‑stroke diesel; mechanical fuel system\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:6px 0;\"\u003eCommon Models\u003c\/td\u003e\n        \u003ctd style=\"padding:6px 0;\"\u003e2GM20, 3GM30 (various cooling and gearbox variants)\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:6px 0;\"\u003eAdvantages\u003c\/td\u003e\n        \u003ctd style=\"padding:6px 0;\"\u003eProven reliability, simple service procedures, compact footprint\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:6px 0;\"\u003eNotes\u003c\/td\u003e\n        \u003ctd style=\"padding:6px 0;\"\u003eService parts vary by cooling setup (raw vs. heat‑exchanger) and gearbox; verify model suffix and serial range.\u003c\/td\u003e\n      \u003c\/tr\u003e\n    \u003c\/tbody\u003e\n  \u003c\/table\u003e\n\n  \u003ch3 style=\"margin-top:20px;\"\u003eYanmar YM Series (e.g., 2YM15, 3YM20, 3YM30)\u003c\/h3\u003e\n  \u003ctable style=\"width:100%;border-collapse:collapse;\"\u003e\n    \u003cthead\u003e\n      \u003ctr\u003e\n        \u003cth style=\"text-align:left;border-bottom:1px solid #e5e7eb;\"\u003eFeature\u003c\/th\u003e\n        \u003cth style=\"text-align:left;border-bottom:1px solid #e5e7eb;\"\u003eDescription\u003c\/th\u003e\n      \u003c\/tr\u003e\n    \u003c\/thead\u003e\n    \u003ctbody\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:6px 0;\"\u003eConfiguration\u003c\/td\u003e\n        \u003ctd style=\"padding:6px 0;\"\u003eInline 2 or 3‑cylinder, naturally aspirated 4‑stroke diesel; refined combustion and compact cooling package\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:6px 0;\"\u003eCommon Models\u003c\/td\u003e\n        \u003ctd style=\"padding:6px 0;\"\u003e2YM15, 3YM20, 3YM30\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:6px 0;\"\u003eAdvantages\u003c\/td\u003e\n        \u003ctd style=\"padding:6px 0;\"\u003eLow vibration\/noise for size, strong fuel economy, easy access to routine service points\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:6px 0;\"\u003eNotes\u003c\/td\u003e\n        \u003ctd style=\"padding:6px 0;\"\u003eMaintenance kits simplify annual service; some filters, belts, and anodes differ from GM‑series—confirm by model code.\u003c\/td\u003e\n      \u003c\/tr\u003e\n    \u003c\/tbody\u003e\n  \u003c\/table\u003e\n\u003c\/section\u003e\n\n\u003csection id=\"service-kits\" style=\"padding:16px;max-width:1000px;\"\u003e\n  \u003ch2\u003eRoutine Maintenance \u0026amp; Service Parts\u003c\/h2\u003e\n  \u003cp\u003eIntervals below are general guidelines; always follow the procedures and schedules in your official Yanmar service manual.\u003c\/p\u003e\n  \u003ctable style=\"width:100%;border-collapse:collapse;\"\u003e\n    \u003cthead\u003e\n      \u003ctr\u003e\n        \u003cth style=\"text-align:left;border-bottom:1px solid #e5e7eb;\"\u003eItem\u003c\/th\u003e\n        \u003cth style=\"text-align:left;border-bottom:1px solid #e5e7eb;\"\u003eInterval*\u003c\/th\u003e\n        \u003cth style=\"text-align:left;border-bottom:1px solid #e5e7eb;\"\u003eRemarks\u003c\/th\u003e\n        \u003cth style=\"text-align:left;border-bottom:1px solid #e5e7eb;\"\u003eParts Link\u003c\/th\u003e\n      \u003c\/tr\u003e\n    \u003c\/thead\u003e\n    \u003ctbody\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:6px 0;\"\u003eEngine oil \u0026amp; oil filter\u003c\/td\u003e\n        \u003ctd style=\"padding:6px 0;\"\u003eEvery 100 hours or annually\u003c\/td\u003e\n        \u003ctd style=\"padding:6px 0;\"\u003eWarm engine before draining; replace crush washer if applicable.\u003c\/td\u003e\n        \u003ctd style=\"padding:6px 0;\"\u003e\u003ca href=\"https:\/\/seasierra.com\/collections\/yanmar-oil-filters\"\u003eYanmar Oil Filters\u003c\/a\u003e\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:6px 0;\"\u003ePrimary\/secondary fuel filters\u003c\/td\u003e\n        \u003ctd style=\"padding:6px 0;\"\u003eEvery 100–200 hours or annually\u003c\/td\u003e\n        \u003ctd style=\"padding:6px 0;\"\u003eDrain water separators; bleed system carefully after filter changes.\u003c\/td\u003e\n        \u003ctd style=\"padding:6px 0;\"\u003e\u003ca href=\"https:\/\/seasierra.com\/collections\/yanmar-fuel-filters\"\u003eYanmar Fuel Filters\u003c\/a\u003e\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:6px 0;\"\u003eRaw‑water impeller\u003c\/td\u003e\n        \u003ctd style=\"padding:6px 0;\"\u003eEvery 200 hours or annually\u003c\/td\u003e\n        \u003ctd style=\"padding:6px 0;\"\u003eInspect for cracked vanes; keep a spare onboard.\u003c\/td\u003e\n        \u003ctd style=\"padding:6px 0;\"\u003e\u003ca href=\"https:\/\/seasierra.com\/collections\/impellers\"\u003eImpellers\u003c\/a\u003e\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:6px 0;\"\u003eAnodes (engine\/heat‑exchanger)\u003c\/td\u003e\n        \u003ctd style=\"padding:6px 0;\"\u003eInspect every 50 hours; replace when 50% consumed\u003c\/td\u003e\n        \u003ctd style=\"padding:6px 0;\"\u003eUse the correct material for your waters (zinc\/aluminum\/magnesium).\u003c\/td\u003e\n        \u003ctd style=\"padding:6px 0;\"\u003e\u003ca href=\"https:\/\/seasierra.com\/collections\/anodes\"\u003eAnodes\u003c\/a\u003e\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:6px 0;\"\u003eAir filter\u003c\/td\u003e\n        \u003ctd style=\"padding:6px 0;\"\u003eInspect every 100 hours; replace 200–300 hours as needed\u003c\/td\u003e\n        \u003ctd style=\"padding:6px 0;\"\u003eReplace sooner in dusty environments; do not over‑oil foam types.\u003c\/td\u003e\n        \u003ctd style=\"padding:6px 0;\"\u003e\u003ca href=\"https:\/\/seasierra.com\/collections\/yanmar-air-filters\"\u003eYanmar Air Filters\u003c\/a\u003e\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:6px 0;\"\u003eDrive\/alternator belt\u003c\/td\u003e\n        \u003ctd style=\"padding:6px 0;\"\u003eInspect every 100 hours; replace 200–300 hours\u003c\/td\u003e\n        \u003ctd style=\"padding:6px 0;\"\u003eCheck tension and pulley alignment; replace if glazed or cracked.\u003c\/td\u003e\n        \u003ctd style=\"padding:6px 0;\"\u003e\u003ca href=\"https:\/\/seasierra.com\/collections\/belt\"\u003eBelts\u003c\/a\u003e\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:6px 0;\"\u003eThermostat \u0026amp; gaskets\u003c\/td\u003e\n        \u003ctd style=\"padding:6px 0;\"\u003eInspect 200 hours; replace as needed\u003c\/td\u003e\n        \u003ctd style=\"padding:6px 0;\"\u003eReplace if overheat issues persist after impeller service.\u003c\/td\u003e\n        \u003ctd style=\"padding:6px 0;\"\u003e\u003ca href=\"https:\/\/seasierra.com\/collections\/yanmar-gaskets\"\u003eYanmar Gaskets\u003c\/a\u003e\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:6px 0;\"\u003eTransmission\/gearbox oil (if applicable)\u003c\/td\u003e\n        \u003ctd style=\"padding:6px 0;\"\u003eEvery 100–200 hours or annually\u003c\/td\u003e\n        \u003ctd style=\"padding:6px 0;\"\u003eFollow gearbox spec for oil type and capacity; check for metal debris.\u003c\/td\u003e\n        \u003ctd style=\"padding:6px 0;\"\u003e\u003ca href=\"https:\/\/seasierra.com\/collections\/yanmar\"\u003eYanmar Collection\u003c\/a\u003e\u003c\/td\u003e\n      \u003c\/tr\u003e\n    \u003c\/tbody\u003e\n  \u003c\/table\u003e\n\u003c\/section\u003e\n\n\u003csection id=\"common-parts\" style=\"padding:16px;max-width:1000px;\"\u003e\n  \u003ch2\u003eFrequently Used Parts Categories\u003c\/h2\u003e\n  \u003cul\u003e\n    \u003cli\u003eRoutine Service – \u003ca href=\"https:\/\/seasierra.com\/collections\/yanmar-service-maintenance-kits\"\u003eYanmar Service \u0026amp; Maintenance Kits\u003c\/a\u003e\n\u003c\/li\u003e\n    \u003cli\u003eFuel System – \u003ca href=\"https:\/\/seasierra.com\/collections\/yanmar-fuel-filters\"\u003eYanmar Fuel Filters\u003c\/a\u003e\n\u003c\/li\u003e\n    \u003cli\u003eLubrication – \u003ca href=\"https:\/\/seasierra.com\/collections\/yanmar-oil-filters\"\u003eYanmar Oil Filters\u003c\/a\u003e\n\u003c\/li\u003e\n    \u003cli\u003eCooling System – \u003ca href=\"https:\/\/seasierra.com\/collections\/impellers\"\u003eImpellers\u003c\/a\u003e and \u003ca href=\"https:\/\/seasierra.com\/collections\/water-pumps\"\u003eWater Pumps\u003c\/a\u003e\n\u003c\/li\u003e\n    \u003cli\u003eAir Intake – \u003ca href=\"https:\/\/seasierra.com\/collections\/yanmar-air-filters\"\u003eYanmar Air Filters\u003c\/a\u003e\n\u003c\/li\u003e\n    \u003cli\u003eExhaust Components – \u003ca href=\"https:\/\/seasierra.com\/collections\/yanmar-elbows\"\u003eYanmar Elbows\u003c\/a\u003e and \u003ca href=\"https:\/\/seasierra.com\/collections\/yanmar-gaskets\"\u003eYanmar Gaskets\u003c\/a\u003e\n\u003c\/li\u003e\n    \u003cli\u003eCorrosion Protection – \u003ca href=\"https:\/\/seasierra.com\/collections\/anodes\"\u003eAnodes\u003c\/a\u003e\n\u003c\/li\u003e\n  \u003c\/ul\u003e\n\u003c\/section\u003e\n\n\u003csection id=\"troubleshooting\" style=\"padding:16px;max-width:1000px;\"\u003e\n  \u003ch2\u003eCommon Symptoms \u0026amp; Quick Checks\u003c\/h2\u003e\n  \u003ctable style=\"width:100%;border-collapse:collapse;\"\u003e\n    \u003cthead\u003e\n      \u003ctr\u003e\n        \u003cth style=\"text-align:left;border-bottom:1px solid #e5e7eb;\"\u003eSymptom\u003c\/th\u003e\n        \u003cth style=\"text-align:left;border-bottom:1px solid #e5e7eb;\"\u003eCheck First\u003c\/th\u003e\n        \u003cth style=\"text-align:left;border-bottom:1px solid #e5e7eb;\"\u003eRelated Parts\u003c\/th\u003e\n      \u003c\/tr\u003e\n    \u003c\/thead\u003e\n    \u003ctbody\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:6px 0;\"\u003eOverheat alarm \/ weak discharge\u003c\/td\u003e\n        \u003ctd style=\"padding:6px 0;\"\u003eInspect sea strainer, intake screen, raw‑water impeller, belt tension, and thermostat.\u003c\/td\u003e\n        \u003ctd style=\"padding:6px 0;\"\u003eWater pump impeller kit, thermostat, belts, anodes\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:6px 0;\"\u003eHard starting \/ stalls after filter change\u003c\/td\u003e\n        \u003ctd style=\"padding:6px 0;\"\u003eCheck for air in fuel lines; bleed at filter and injection pump; verify filter orientation and seals.\u003c\/td\u003e\n        \u003ctd style=\"padding:6px 0;\"\u003eFuel filters, service kit gaskets\/washers, hoses\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:6px 0;\"\u003ePoor acceleration \/ power loss under load\u003c\/td\u003e\n        \u003ctd style=\"padding:6px 0;\"\u003eConfirm clean fuel and filters; check air filter restriction; inspect exhaust elbow for carbon\/salt buildup; verify propeller cleanliness.\u003c\/td\u003e\n        \u003ctd style=\"padding:6px 0;\"\u003eFuel filters, air filter, exhaust elbow, gaskets\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:6px 0;\"\u003eExcessive smoke (black\/white)\u003c\/td\u003e\n        \u003ctd style=\"padding:6px 0;\"\u003eBlack: air restriction or overload. White: cold operation or injector\/fuel quality issues.\u003c\/td\u003e\n        \u003ctd style=\"padding:6px 0;\"\u003eAir filter, fuel filters, service kits\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:6px 0;\"\u003eGearbox noise or metallic debris\u003c\/td\u003e\n        \u003ctd style=\"padding:6px 0;\"\u003eVerify oil level\/condition; check alignment and mounts; change oil and inspect magnetic plug.\u003c\/td\u003e\n        \u003ctd style=\"padding:6px 0;\"\u003eService kits, gaskets, anodes\u003c\/td\u003e\n      \u003c\/tr\u003e\n    \u003c\/tbody\u003e\n  \u003c\/table\u003e\n\u003c\/section\u003e\n\n\u003csection id=\"faq\" style=\"padding:16px;max-width:1000px;\"\u003e\n  \u003ch2\u003eFAQs\u003c\/h2\u003e\n  \u003cdetails\u003e\n    \u003csummary\u003eAre parts interchangeable between GM and YM series engines?\u003c\/summary\u003e\n    \u003cp\u003eSome service items may look similar but differ in size or specification between GM and YM platforms. Always confirm by model code, serial number, and cooling\/gearbox configuration before ordering.\u003c\/p\u003e\n  \u003c\/details\u003e\n  \u003cdetails\u003e\n    \u003csummary\u003eWhen should I replace the raw‑water impeller?\u003c\/summary\u003e\n    \u003cp\u003eAs a rule of thumb, replace annually or every 200 hours—sooner if operating in sandy, silty, or debris‑prone waters, or if discharge weakens or blades show cracking.\u003c\/p\u003e\n  \u003c\/details\u003e\n  \u003cdetails\u003e\n    \u003csummary\u003eHow often should transmission\/gearbox oil be changed?\u003c\/summary\u003e\n    \u003cp\u003eMost small marine gearboxes specify 100–200 hour or annual changes. Follow the gearbox’s specific oil type and capacity, and inspect the drain plug for metal particles.\u003c\/p\u003e\n  \u003c\/details\u003e\n  \u003cdetails\u003e\n    \u003csummary\u003eWhat information helps confirm part compatibility?\u003c\/summary\u003e\n    \u003cp\u003eProvide the full engine model code (including suffix), serial number, gearbox model\/ratio, and cooling type (raw vs. freshwater with heat‑exchanger). Photos of the nameplate and the part being replaced are very helpful.\u003c\/p\u003e\n  \u003c\/details\u003e\n\u003c\/section\u003e\n\n\u003csection id=\"cta\" style=\"padding:16px;border-top:1px solid #e5e7eb;max-width:1000px;\"\u003e\n  \u003cp\u003eReady to find parts by horsepower, year, and model? Browse our main Yanmar collection and use the filters to narrow to your setup.\u003c\/p\u003e\n  \u003cp\u003e\u003ca href=\"https:\/\/seasierra.com\/collections\/yanmar\" style=\"display:inline-block;padding:10px 14px;background:#0d6efd;color:#fff;text-decoration:none;border-radius:6px;\"\u003eShop Yanmar Parts\u003c\/a\u003e\u003c\/p\u003e\n  \u003cp style=\"font-size:0.95em;color:#374151;\"\u003eIf you’re unsure about your model, send us a photo of the nameplate and the part you need and we’ll help verify compatibility.\u003c\/p\u003e\n\u003c\/section\u003e","products":[{"product_id":"v-belt-fits-yanmar-2gm-3gm-series-replaces-25132-003100-25132-003000-128670-77350","title":"Replacement Alternator Belt for Yanmar 2GM20, 2GM20-YEU \u0026 2GMLP – Reference 25132-003100","description":"\u003csection\u003e\n\u003c!-- 🔧 Table Styles (include only once per page) --\u003e\n\u003cstyle\u003e\n  .ss-table-wrap { overflow-x:auto; -webkit-overflow-scrolling:touch; }\n  table.ss-table { width:100%; border-collapse:collapse; min-width:640px; }\n  table.ss-table th, table.ss-table td {\n    padding:10px 12px; border:1px solid #e5e7eb; text-align:left; vertical-align:top;\n  }\n  table.ss-table th {\n    white-space:nowrap;\n    word-break:normal;\n    letter-spacing:normal;\n    font-weight:600;\n    background:#f8fafc;\n  }\n  @media (max-width:480px){\n    table.ss-table th, table.ss-table td { padding:8px 10px; font-size:14px; }\n  }\n\u003c\/style\u003e\n\n\u003ch2\u003eProduct Details\u003c\/h2\u003e\n\u003cp\u003eThis replacement \u003cstrong\u003ealternator belt\u003c\/strong\u003e is listed for Yanmar Marine inboard engines including the \u003cstrong\u003e2GM20, 2GM20-YEU, and 2GMLP\u003c\/strong\u003e. The belt is designed for the engine charging system and runs between the engine pulleys to drive the alternator.\u003c\/p\u003e\n\u003cp\u003eThe company catalog identifies this product as a single marine belt and lists \u003cstrong\u003eYanmar reference number 25132-003100\u003c\/strong\u003e. Confirm the model designation and the number on your existing belt before ordering.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eReplacement belt for the alternator drive system.\u003c\/li\u003e\n  \u003cli\u003eListed for selected Yanmar 2GM-series marine inboard engines.\u003c\/li\u003e\n  \u003cli\u003eSupplied as one individual belt.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2\u003ePart Number Reference\u003c\/h2\u003e\n\u003cp\u003eUse the following reference to compare the belt with your existing part and engine documentation.\u003c\/p\u003e\n\u003cdiv class=\"ss-table-wrap\"\u003e\n  \u003ctable class=\"ss-table\" aria-label=\"Part Number Reference\"\u003e\n    \u003cthead\u003e\n      \u003ctr\u003e\n        \u003cth\u003eBrand\u003c\/th\u003e\n        \u003cth\u003eReference Number\u003c\/th\u003e\n        \u003cth\u003eApplication\u003c\/th\u003e\n      \u003c\/tr\u003e\n    \u003c\/thead\u003e\n    \u003ctbody\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eYanmar\u003c\/td\u003e\n        \u003ctd\u003e25132-003100\u003c\/td\u003e\n        \u003ctd\u003eAlternator belt reference listed for this product.\u003c\/td\u003e\n      \u003c\/tr\u003e\n    \u003c\/tbody\u003e\n  \u003c\/table\u003e\n\u003c\/div\u003e\n\n\u003ch2\u003eEngine Compatibility\u003c\/h2\u003e\n\u003cp\u003eThe company fitment record lists the following Yanmar Marine inboard engine models. Keep the complete model designation together when checking compatibility.\u003c\/p\u003e\n\u003cdiv class=\"ss-table-wrap\"\u003e\n  \u003ctable class=\"ss-table\" aria-label=\"Engine Compatibility\"\u003e\n    \u003cthead\u003e\n      \u003ctr\u003e\n        \u003cth\u003eBrand\u003c\/th\u003e\n        \u003cth\u003eEngine Model\u003c\/th\u003e\n        \u003cth\u003eStroke\u003c\/th\u003e\n        \u003cth\u003eReference Number\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\u003eYanmar Marine Inboard\u003c\/td\u003e\n        \u003ctd\u003e2GM20\u003c\/td\u003e\n        \u003ctd\u003eNot specified\u003c\/td\u003e\n        \u003ctd\u003e25132-003100\u003c\/td\u003e\n        \u003ctd\u003eConfirm the exact model designation before ordering.\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eYanmar Marine Inboard\u003c\/td\u003e\n        \u003ctd\u003e2GM20-YEU\u003c\/td\u003e\n        \u003ctd\u003eNot specified\u003c\/td\u003e\n        \u003ctd\u003e25132-003100\u003c\/td\u003e\n        \u003ctd\u003eConfirm the exact model designation before ordering.\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eYanmar Marine Inboard\u003c\/td\u003e\n        \u003ctd\u003e2GMLP\u003c\/td\u003e\n        \u003ctd\u003eNot specified\u003c\/td\u003e\n        \u003ctd\u003e25132-003100\u003c\/td\u003e\n        \u003ctd\u003eConfirm the exact model designation before ordering.\u003c\/td\u003e\n      \u003c\/tr\u003e\n    \u003c\/tbody\u003e\n  \u003c\/table\u003e\n\u003c\/div\u003e\n\n\u003ch2\u003eTechnical Information\u003c\/h2\u003e\n\u003cdl\u003e\n  \u003cdt\u003eProduct Type\u003c\/dt\u003e\n  \u003cdd\u003eMarine alternator belt\u003c\/dd\u003e\n  \u003cdt\u003eProduct Configuration\u003c\/dt\u003e\n  \u003cdd\u003eSingle belt\u003c\/dd\u003e\n  \u003cdt\u003eListed Engine Brand\u003c\/dt\u003e\n  \u003cdd\u003eYanmar Marine Inboard\u003c\/dd\u003e\n  \u003cdt\u003eListed Engine Models\u003c\/dt\u003e\n  \u003cdd\u003e2GM20, 2GM20-YEU, and 2GMLP\u003c\/dd\u003e\n  \u003cdt\u003eReference Number\u003c\/dt\u003e\n  \u003cdd\u003e25132-003100\u003c\/dd\u003e\n  \u003cdt\u003eDimensions\u003c\/dt\u003e\n  \u003cdd\u003eNot specified in the company product record. Compare the replacement belt with the original before installation.\u003c\/dd\u003e\n  \u003cdt\u003eMaterial\u003c\/dt\u003e\n  \u003cdd\u003eNot specified in the company product record.\u003c\/dd\u003e\n\u003c\/dl\u003e\n\n\u003ch2\u003eWhat’s in the Box\u003c\/h2\u003e\n\u003cul\u003e\n  \u003cli\u003e\n\u003cspan style=\"color:#d0021b;\"\u003e1 x\u003c\/span\u003e Replacement alternator belt\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2\u003eInstallation Notes\u003c\/h2\u003e\n\u003col\u003e\n  \u003cli\u003eTurn off the engine, allow it to cool, and prevent accidental starting before beginning work.\u003c\/li\u003e\n  \u003cli\u003eDisconnect the battery if required by the engine manufacturer’s service procedure.\u003c\/li\u003e\n  \u003cli\u003eInspect the original belt routing and identify the pulleys driven by the belt.\u003c\/li\u003e\n  \u003cli\u003eLoosen the alternator adjustment hardware enough to release belt tension.\u003c\/li\u003e\n  \u003cli\u003eRemove the old belt and inspect the pulley grooves for wear, corrosion, contamination, or damage.\u003c\/li\u003e\n  \u003cli\u003eInstall the replacement belt along the original routing, making sure it is seated correctly in every pulley groove.\u003c\/li\u003e\n  \u003cli\u003eAdjust the belt tension according to the Yanmar engine service manual. Do not overtighten the belt.\u003c\/li\u003e\n  \u003cli\u003eTighten the adjustment and mounting hardware to the manufacturer’s specified torque.\u003c\/li\u003e\n  \u003cli\u003eReconnect the battery if it was disconnected, then run the engine briefly and check belt tracking and operation.\u003c\/li\u003e\n  \u003cli\u003eStop the engine and recheck the belt after operation. Adjust only according to the engine manufacturer’s instructions.\u003c\/li\u003e\n\u003c\/ol\u003e\n\n\u003ch2\u003eTroubleshooting \u0026amp; FAQ\u003c\/h2\u003e\n\u003cdetails\u003e\u003csummary\u003eHow do I know if this belt fits my engine?\u003c\/summary\u003e\u003cp\u003eCheck that your engine is a Yanmar 2GM20, 2GM20-YEU, or 2GMLP and compare the existing belt with reference number 25132-003100. Model, designation, pulley arrangement, and belt dimensions should all be checked before ordering.\u003c\/p\u003e\u003c\/details\u003e\n\u003cdetails\u003e\u003csummary\u003eIs this belt for the alternator?\u003c\/summary\u003e\u003cp\u003eYes. The company product record identifies it as an alternator belt for the listed Yanmar Marine inboard applications.\u003c\/p\u003e\u003c\/details\u003e\n\u003cdetails\u003e\u003csummary\u003eHow many belts are included?\u003c\/summary\u003e\u003cp\u003eThis is a single-belt product. The package contains one replacement alternator belt.\u003c\/p\u003e\u003c\/details\u003e\n\u003cdetails\u003e\u003csummary\u003eWhat should I check before installation?\u003c\/summary\u003e\u003cp\u003eCheck the belt routing, pulley grooves, belt condition, and the exact engine model. Replace or repair worn pulleys and follow the Yanmar service manual for tension and torque specifications.\u003c\/p\u003e\u003c\/details\u003e\n\u003cdetails\u003e\u003csummary\u003eWhat are signs that the belt may need attention?\u003c\/summary\u003e\u003cp\u003eInspect for cracking, fraying, glazing, contamination, abnormal noise, slipping, or visible damage. Charging-system problems may have several causes, so inspect the belt and the complete charging system before replacing parts.\u003c\/p\u003e\u003c\/details\u003e\n\u003cdetails\u003e\u003csummary\u003eIs this an OEM Yanmar belt?\u003c\/summary\u003e\u003cp\u003eThe product is listed as a replacement belt with Yanmar reference number 25132-003100. The available product record does not explicitly identify it as genuine Yanmar original equipment.\u003c\/p\u003e\u003c\/details\u003e\n\n\u003ch2\u003eSafety \u0026amp; Important Information\u003c\/h2\u003e\n\u003cul\u003e\n  \u003cli\u003eVerify the exact engine model and the original belt reference before purchase.\u003c\/li\u003e\n  \u003cli\u003eDo not install a belt that differs in profile, length, or fit from the original application.\u003c\/li\u003e\n  \u003cli\u003eKeep hands, clothing, and tools clear of rotating components while the engine is running.\u003c\/li\u003e\n  \u003cli\u003eFollow the applicable Yanmar service manual for belt tension, fastener torque, and maintenance intervals.\u003c\/li\u003e\n  \u003cli\u003eProfessional installation is recommended if the belt routing or adjustment procedure is uncertain.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2\u003eAbout Sea Sierra\u003c\/h2\u003e\n\u003cul\u003e\n  \u003cli\u003eMarine replacement parts selected for practical service and maintenance applications.\u003c\/li\u003e\n  \u003cli\u003eClear product references and application information to help support accurate part selection.\u003c\/li\u003e\n  \u003cli\u003eGlobal fulfillment options are available where offered at checkout.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/section\u003e","brand":"SeaSierra","offers":[{"title":"Default Title","offer_id":50723789504827,"sku":"23BL237","price":16.5,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0826\/8673\/8747\/files\/23BL237_1.jpg?v=1763031816"}],"url":"https:\/\/seasierra.com\/collections\/yanmar-4-stroke-18-30hp-marine-engine-parts.oembed","provider":"SeaSierra","version":"1.0","type":"link"}