{"title":"JLM 4-Stroke 28HP Marine Engine Parts","description":"\u003csection id=\"hero\" style=\"padding:16px;border:1px solid #e5e7eb;border-radius:8px;max-width:960px;margin:0 auto 20px;\"\u003e\n  \u003cp\u003eThis page is dedicated to JLM 4‑Stroke 28HP outboard engines. Use it to find compatible parts and practical service information. Below you’ll find maintenance tips, common replacement parts, and troubleshooting guidance. You can also browse our main JLM collection if you prefer a broader view of parts. Scroll to the bottom of this page to start browsing parts for this engine, and remember you can use the “Filter \u0026amp; Sort” controls on collection pages to narrow results by horsepower, year range, and part category.\u003c\/p\u003e\n  \u003ca href=\"https:\/\/seasierra.com\/collections\/johnson-evinrude-omc-outboard-parts\" style=\"display:inline-block;padding:10px 14px;background:#004aad;color:#fff;text-decoration:none;border-radius:6px;\"\u003eBrowse All JLM Parts\u003c\/a\u003e\n\u003c\/section\u003e\n\n\u003csection id=\"identify-model\" style=\"max-width:960px;margin:0 auto 24px;\"\u003e\n  \u003ch2\u003eHow to Identify Your 28HP Model\u003c\/h2\u003e\n  \u003cul\u003e\n    \u003cli\u003eLocate the nameplate\/serial plate on the transom bracket or swivel bracket. It typically lists model, serial number, and build details.\u003c\/li\u003e\n    \u003cli\u003eDecode the model suffix: letters often indicate tiller vs. remote, electric start, trim\/tilt, and shaft length (S\/L\/XL). A year code or production code may be present.\u003c\/li\u003e\n    \u003cli\u003eConfirm it’s a 4‑stroke: look for an engine oil fill\/dipstick and an oil filter canister (2‑strokes won’t have a crankcase oil system).\u003c\/li\u003e\n    \u003cli\u003eNote features like fuel delivery (carbureted vs. EFI) and charging output; these help match ignition, fuel, and electrical parts.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\u003c\/section\u003e\n\n\u003csection id=\"engine-overview\" style=\"max-width:960px;margin:0 auto 24px;\"\u003e\n  \u003ch2\u003eEngine Overview\u003c\/h2\u003e\n  \u003ch3\u003e28HP 4‑Stroke Small‑Outboard Platform\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;padding:8px;\"\u003eFeature\u003c\/th\u003e\n        \u003cth style=\"text-align:left;border-bottom:1px solid #e5e7eb;padding:8px;\"\u003eDescription\u003c\/th\u003e\n      \u003c\/tr\u003e\n    \u003c\/thead\u003e\n    \u003ctbody\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:8px;border-bottom:1px solid #f1f5f9;\"\u003eConfiguration\u003c\/td\u003e\n        \u003ctd style=\"padding:8px;border-bottom:1px solid #f1f5f9;\"\u003eCompact 4‑stroke, typically a small inline multi‑cylinder with carburetor or EFI, designed for lightweight utility and fishing boats.\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:8px;border-bottom:1px solid #f1f5f9;\"\u003eCommon Models\u003c\/td\u003e\n        \u003ctd style=\"padding:8px;border-bottom:1px solid #f1f5f9;\"\u003eGeneral 25–30 HP 4‑stroke class outboards with similar gearcases and service parts; verify by model\/serial for best fit.\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:8px;border-bottom:1px solid #f1f5f9;\"\u003eAdvantages\u003c\/td\u003e\n        \u003ctd style=\"padding:8px;border-bottom:1px solid #f1f5f9;\"\u003eLow fuel consumption, quieter operation, broad torque curve for planing small hulls, and clean emissions.\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:8px;border-bottom:1px solid #f1f5f9;\"\u003eNotes\u003c\/td\u003e\n        \u003ctd style=\"padding:8px;border-bottom:1px solid #f1f5f9;\"\u003eMany wear items (impeller, spark plugs, anodes) are shared across the 25–30 HP family; always confirm shaft length, controls, and fuel system type before ordering.\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=\"max-width:960px;margin:0 auto 24px;\"\u003e\n  \u003ch2\u003eRoutine Maintenance \u0026amp; Service Parts\u003c\/h2\u003e\n  \u003cp\u003eIntervals below are general guidelines for typical recreational use. Always follow the official service manual for your exact model and operating conditions.\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;padding:8px;\"\u003eItem\u003c\/th\u003e\n        \u003cth style=\"text-align:left;border-bottom:1px solid #e5e7eb;padding:8px;\"\u003eInterval*\u003c\/th\u003e\n        \u003cth style=\"text-align:left;border-bottom:1px solid #e5e7eb;padding:8px;\"\u003eRemarks\u003c\/th\u003e\n        \u003cth style=\"text-align:left;border-bottom:1px solid #e5e7eb;padding:8px;\"\u003eParts Link\u003c\/th\u003e\n      \u003c\/tr\u003e\n    \u003c\/thead\u003e\n    \u003ctbody\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:8px;border-bottom:1px solid #f1f5f9;\"\u003eEngine oil + filter\u003c\/td\u003e\n        \u003ctd style=\"padding:8px;border-bottom:1px solid #f1f5f9;\"\u003eAfter 20 hrs (break‑in), then every 100 hrs or annually\u003c\/td\u003e\n        \u003ctd style=\"padding:8px;border-bottom:1px solid #f1f5f9;\"\u003eUse marine‑grade FC‑W oil; replace filter at each oil change.\u003c\/td\u003e\n        \u003ctd style=\"padding:8px;border-bottom:1px solid #f1f5f9;\"\u003e\u003ca href=\"https:\/\/seasierra.com\/collections\/oil-filters\"\u003eOil Filters\u003c\/a\u003e\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:8px;border-bottom:1px solid #f1f5f9;\"\u003eGear oil (lower unit)\u003c\/td\u003e\n        \u003ctd style=\"padding:8px;border-bottom:1px solid #f1f5f9;\"\u003eEvery 100 hrs or annually\u003c\/td\u003e\n        \u003ctd style=\"padding:8px;border-bottom:1px solid #f1f5f9;\"\u003eChange more often if water intrusion or heavy use; inspect drain plug magnets.\u003c\/td\u003e\n        \u003ctd style=\"padding:8px;border-bottom:1px solid #f1f5f9;\"\u003e\u003ca href=\"https:\/\/seasierra.com\/collections\/lower-unit-seal-kits\"\u003eLower Unit Seal Kits\u003c\/a\u003e\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:8px;border-bottom:1px solid #f1f5f9;\"\u003eSpark plugs\u003c\/td\u003e\n        \u003ctd style=\"padding:8px;border-bottom:1px solid #f1f5f9;\"\u003eInspect every 100 hrs; replace as needed or every 200 hrs\u003c\/td\u003e\n        \u003ctd style=\"padding:8px;border-bottom:1px solid #f1f5f9;\"\u003eCheck gap and condition; fouling indicates mixture or ignition issues.\u003c\/td\u003e\n        \u003ctd style=\"padding:8px;border-bottom:1px solid #f1f5f9;\"\u003e\u003ca href=\"https:\/\/seasierra.com\/collections\/spark-plug\"\u003eSpark Plugs\u003c\/a\u003e\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:8px;border-bottom:1px solid #f1f5f9;\"\u003eFuel filter \/ water‑separating filter\u003c\/td\u003e\n        \u003ctd style=\"padding:8px;border-bottom:1px solid #f1f5f9;\"\u003eEvery 100 hrs or annually\u003c\/td\u003e\n        \u003ctd style=\"padding:8px;border-bottom:1px solid #f1f5f9;\"\u003eReplace more often with ethanol fuel or contaminated supply.\u003c\/td\u003e\n        \u003ctd style=\"padding:8px;border-bottom:1px solid #f1f5f9;\"\u003e\u003ca href=\"https:\/\/seasierra.com\/collections\/fuel-filters-1\"\u003eFuel Filters\u003c\/a\u003e\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:8px;border-bottom:1px solid #f1f5f9;\"\u003eWater pump impeller \/ kit\u003c\/td\u003e\n        \u003ctd style=\"padding:8px;border-bottom:1px solid #f1f5f9;\"\u003eEvery 2 seasons (or 200 hrs); annually in sandy\/silty water\u003c\/td\u003e\n        \u003ctd style=\"padding:8px;border-bottom:1px solid #f1f5f9;\"\u003eCritical for cooling; replace housing\/plate if scored.\u003c\/td\u003e\n        \u003ctd style=\"padding:8px;border-bottom:1px solid #f1f5f9;\"\u003e\u003ca href=\"https:\/\/seasierra.com\/collections\/water-pump-impeller-rebuild-kits\"\u003eWater Pump Impeller Rebuild Kits\u003c\/a\u003e\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:8px;border-bottom:1px solid #f1f5f9;\"\u003eAnodes (zincs\/aluminum)\u003c\/td\u003e\n        \u003ctd style=\"padding:8px;border-bottom:1px solid #f1f5f9;\"\u003eInspect every 50 hrs; replace when 50% consumed\u003c\/td\u003e\n        \u003ctd style=\"padding:8px;border-bottom:1px solid #f1f5f9;\"\u003eChoose the correct alloy for fresh, brackish, or saltwater.\u003c\/td\u003e\n        \u003ctd style=\"padding:8px;border-bottom:1px solid #f1f5f9;\"\u003e\u003ca href=\"https:\/\/seasierra.com\/collections\/anodes\"\u003eAnodes\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=\"max-width:960px;margin:0 auto 24px;\"\u003e\n  \u003ch2\u003eFrequently Used Parts Categories\u003c\/h2\u003e\n  \u003cul\u003e\n    \u003cli\u003eRoutine Service: \u003ca href=\"https:\/\/seasierra.com\/collections\/service-maintenance-kits\"\u003eService \u0026amp; Maintenance Kits\u003c\/a\u003e\n\u003c\/li\u003e\n    \u003cli\u003eCooling System: \u003ca href=\"https:\/\/seasierra.com\/collections\/water-pump-impeller-rebuild-kits\"\u003eWater Pump Impeller Kits\u003c\/a\u003e\n\u003c\/li\u003e\n    \u003cli\u003eFuel System: \u003ca href=\"https:\/\/seasierra.com\/collections\/fuel-filters-1\"\u003eFuel Filters\u003c\/a\u003e and \u003ca href=\"https:\/\/seasierra.com\/collections\/fuel-pumps\"\u003eFuel Pumps\u003c\/a\u003e\n\u003c\/li\u003e\n    \u003cli\u003eIgnition \/ Electrical: \u003ca href=\"https:\/\/seasierra.com\/collections\/electrical-items\"\u003eElectrical Items\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    \u003cli\u003eSealing \u0026amp; Repairs: \u003ca href=\"https:\/\/seasierra.com\/collections\/gaskets\"\u003eGaskets\u003c\/a\u003e and \u003ca href=\"https:\/\/seasierra.com\/collections\/lower-unit-seal-kits\"\u003eLower Unit Seal Kits\u003c\/a\u003e\n\u003c\/li\u003e\n    \u003cli\u003ePropulsion \u0026amp; Trim: \u003ca href=\"https:\/\/seasierra.com\/collections\/propellers\"\u003ePropellers\u003c\/a\u003e and \u003ca href=\"https:\/\/seasierra.com\/collections\/boat-accessories\"\u003eBoat Accessories\u003c\/a\u003e\n\u003c\/li\u003e\n  \u003c\/ul\u003e\n\u003c\/section\u003e\n\n\u003csection id=\"troubleshooting\" style=\"max-width:960px;margin:0 auto 24px;\"\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;padding:8px;\"\u003eSymptom\u003c\/th\u003e\n        \u003cth style=\"text-align:left;border-bottom:1px solid #e5e7eb;padding:8px;\"\u003eCheck First\u003c\/th\u003e\n        \u003cth style=\"text-align:left;border-bottom:1px solid #e5e7eb;padding:8px;\"\u003eRelated Parts\u003c\/th\u003e\n      \u003c\/tr\u003e\n    \u003c\/thead\u003e\n    \u003ctbody\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:8px;border-bottom:1px solid #f1f5f9;\"\u003eWeak tell‑tale stream or overheat alarm\u003c\/td\u003e\n        \u003ctd style=\"padding:8px;border-bottom:1px solid #f1f5f9;\"\u003eInspect intake screens for debris; verify impeller age; check thermostat for sticking.\u003c\/td\u003e\n        \u003ctd style=\"padding:8px;border-bottom:1px solid #f1f5f9;\"\u003eWater pump kit, thermostat, intake screens, gaskets\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:8px;border-bottom:1px solid #f1f5f9;\"\u003ePoor acceleration or power loss\u003c\/td\u003e\n        \u003ctd style=\"padding:8px;border-bottom:1px solid #f1f5f9;\"\u003eReplace fuel filter; inspect spark plugs; check prop for damage\/cavitation; confirm clean fuel.\u003c\/td\u003e\n        \u003ctd style=\"padding:8px;border-bottom:1px solid #f1f5f9;\"\u003eFuel filter, spark plugs, fuel pump, propeller\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:8px;border-bottom:1px solid #f1f5f9;\"\u003eHard starting or rough idle\u003c\/td\u003e\n        \u003ctd style=\"padding:8px;border-bottom:1px solid #f1f5f9;\"\u003ePrime fuel line; look for air leaks at connectors; verify idle speed; inspect plugs and ignition leads.\u003c\/td\u003e\n        \u003ctd style=\"padding:8px;border-bottom:1px solid #f1f5f9;\"\u003eFuel line\/connector, fuel pump, spark plugs, electrical components\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:8px;border-bottom:1px solid #f1f5f9;\"\u003eGearcase noise or metal in gear oil\u003c\/td\u003e\n        \u003ctd style=\"padding:8px;border-bottom:1px solid #f1f5f9;\"\u003eDrain gear oil and inspect; check prop shaft for fishing line; pressure\/vacuum test seals.\u003c\/td\u003e\n        \u003ctd style=\"padding:8px;border-bottom:1px solid #f1f5f9;\"\u003eLower unit seal kit, gaskets, gear oil, prop shaft hardware\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd style=\"padding:8px;border-bottom:1px solid #f1f5f9;\"\u003eExcessive vibration\u003c\/td\u003e\n        \u003ctd style=\"padding:8px;border-bottom:1px solid #f1f5f9;\"\u003eInspect prop for bent blades; check engine mounts; verify correct propeller hub and balance.\u003c\/td\u003e\n        \u003ctd style=\"padding:8px;border-bottom:1px solid #f1f5f9;\"\u003ePropeller, prop hub, mounts, hardware\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=\"max-width:960px;margin:0 auto 24px;\"\u003e\n  \u003ch2\u003eFAQs\u003c\/h2\u003e\n  \u003cdetails\u003e\n    \u003csummary\u003eAre parts interchangeable across different years in the 25–30 HP range?\u003c\/summary\u003e\n    \u003cp\u003eMany wear items are shared across the 25–30 HP 4‑stroke family, but ignition, fuel, and control components can vary by year and sub‑model. Always confirm with your model\/serial and key features (carb vs. EFI, shaft length, control type) before ordering.\u003c\/p\u003e\n  \u003c\/details\u003e\n  \u003cdetails\u003e\n    \u003csummary\u003eWhen should I replace the water pump impeller?\u003c\/summary\u003e\n    \u003cp\u003eReplace every two seasons (or about 200 hours), and annually if you operate in sandy or silty water. Replace the full kit when the wear plate or housing shows scoring.\u003c\/p\u003e\n  \u003c\/details\u003e\n  \u003cdetails\u003e\n    \u003csummary\u003eHow often should I change lower unit gear oil?\u003c\/summary\u003e\n    \u003cp\u003eAt least once per year or every 100 hours. Inspect for water intrusion or metal on the magnet; address seal issues immediately if contamination is found.\u003c\/p\u003e\n  \u003c\/details\u003e\n  \u003cdetails\u003e\n    \u003csummary\u003eWhat information do you need to verify part compatibility?\u003c\/summary\u003e\n    \u003cp\u003eProvide the model and serial numbers from the nameplate, shaft length (S\/L\/XL), control type (tiller\/remote), starting\/charging options, and whether the engine is carbureted or EFI.\u003c\/p\u003e\n  \u003c\/details\u003e\n\u003c\/section\u003e\n\n\u003csection id=\"cta\" style=\"padding:16px;border:1px solid #e5e7eb;border-radius:8px;max-width:960px;margin:0 auto;\"\u003e\n  \u003cp\u003eReady to find parts for your JLM 4‑Stroke 28HP? Browse our main collection by horsepower, year, and model to zero in on what you need.\u003c\/p\u003e\n  \u003ca href=\"https:\/\/seasierra.com\/collections\/johnson-evinrude-omc-outboard-parts\" style=\"display:inline-block;margin-top:8px;padding:10px 14px;background:#004aad;color:#fff;text-decoration:none;border-radius:6px;\"\u003eBrowse All JLM Parts\u003c\/a\u003e\n  \u003cp style=\"margin-top:8px;color:#475569;\"\u003eIf you’re unsure about your model, send us a clear photo of the nameplate and the part you need and we’ll help verify compatibility.\u003c\/p\u003e\n\u003c\/section\u003e","products":[],"url":"https:\/\/seasierra.com\/collections\/jlm-4-stroke-28hp-marine-engine-parts.oembed","provider":"SeaSierra","version":"1.0","type":"link"}