{"title":"4-Stroke Marine Engine Parts","description":"\u003csection id=\"hero\" style=\"padding:16px; border:1px solid #eee; border-radius:8px;\"\u003e\n  \u003cp\u003eThis page is for 4‑Stroke marine outboard engines. It helps you find compatible parts and service information, with maintenance tips, common replacement parts, and troubleshooting guidance. You can also browse our main brand collections, including \u003ca href=\"https:\/\/seasierra.com\/collections\/yamaha\" style=\"text-decoration:underline;\"\u003eYamaha\u003c\/a\u003e, \u003ca href=\"https:\/\/seasierra.com\/collections\/mercury-outboard-parts\" style=\"text-decoration:underline;\"\u003eMercury\u003c\/a\u003e, \u003ca href=\"https:\/\/seasierra.com\/collections\/suzuki\" style=\"text-decoration:underline;\"\u003eSuzuki\u003c\/a\u003e, \u003ca href=\"https:\/\/seasierra.com\/collections\/honda-outboard-parts\" style=\"text-decoration:underline;\"\u003eHonda\u003c\/a\u003e, \u003ca href=\"https:\/\/seasierra.com\/collections\/johnson-evinrude\" style=\"text-decoration:underline;\"\u003eJohnson\/Evinrude\u003c\/a\u003e, and \u003ca href=\"https:\/\/seasierra.com\/collections\/volvo-penta\" style=\"text-decoration:underline;\"\u003eVolvo Penta\u003c\/a\u003e. Scroll to the bottom of this page to start browsing parts for your engine. On the collection pages, use the Filter \u0026amp; Sort controls to narrow results by horsepower, year range, and part category\/section.\u003c\/p\u003e\n  \u003cp\u003e\u003ca href=\"https:\/\/seasierra.com\/collections\/service-maintenance-kits\" style=\"display:inline-block; padding:10px 14px; border:1px solid #0a5; border-radius:6px; text-decoration:none;\"\u003eShop Service \u0026amp; Maintenance Kits\u003c\/a\u003e\u003c\/p\u003e\n\u003c\/section\u003e\n\n\u003csection id=\"identify-model\"\u003e\n  \u003ch2\u003eHow to Identify Your 4‑Stroke Model\u003c\/h2\u003e\n  \u003cul\u003e\n    \u003cli\u003eFind the nameplate\/serial plate: usually on the transom bracket or swivel bracket. It lists model code, serial number, and sometimes a year or production code.\u003c\/li\u003e\n    \u003cli\u003eDecode the model suffix: letters\/numbers often indicate shaft length (S\/L\/XL), starting method (manual\/electric), control type (tiller\/remote), and other options.\u003c\/li\u003e\n    \u003cli\u003eConfirm it is a 4‑Stroke: look for an engine oil fill cap and dipstick on the powerhead and an oil filter canister on many models.\u003c\/li\u003e\n    \u003cli\u003eNote gearcase and shaft length: impellers, anodes, and props can vary by gearcase size and shaft length (measure from bracket mounting surface to cavitation plate).\u003c\/li\u003e\n  \u003c\/ul\u003e\n\u003c\/section\u003e\n\n\u003csection id=\"engine-overview\"\u003e\n  \u003ch2\u003ePlatform Overview\u003c\/h2\u003e\n  \u003ch3\u003eSmall Outboards (Portable Class)\u003c\/h3\u003e\n  \u003ctable style=\"width:100%; max-width:900px; border-collapse:collapse;\"\u003e\n    \u003cthead\u003e\n      \u003ctr\u003e\n        \u003cth style=\"text-align:left; border-bottom:1px solid #ddd;\"\u003eFeature\u003c\/th\u003e\n        \u003cth style=\"text-align:left; border-bottom:1px solid #ddd;\"\u003eDescription\u003c\/th\u003e\n      \u003c\/tr\u003e\n    \u003c\/thead\u003e\n    \u003ctbody\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eConfiguration\u003c\/td\u003e\n        \u003ctd\u003eInline 1–3 cylinder 4‑Stroke, carbureted or EFI; manual or electric start.\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eCommon Models\u003c\/td\u003e\n        \u003ctd\u003ePortable 4‑Stroke outboards in the 2.5–20 HP range.\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eAdvantages\u003c\/td\u003e\n        \u003ctd\u003eLight weight, easy handling, quiet operation, excellent fuel economy.\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eNotes\u003c\/td\u003e\n        \u003ctd\u003eImpeller and anode styles vary by gearcase; spark plug heat range and gap are model‑specific.\u003c\/td\u003e\n      \u003c\/tr\u003e\n    \u003c\/tbody\u003e\n  \u003c\/table\u003e\n\n  \u003ch3\u003eMid‑Range Outboards\u003c\/h3\u003e\n  \u003ctable style=\"width:100%; max-width:900px; border-collapse:collapse;\"\u003e\n    \u003cthead\u003e\n      \u003ctr\u003e\n        \u003cth style=\"text-align:left; border-bottom:1px solid #ddd;\"\u003eFeature\u003c\/th\u003e\n        \u003cth style=\"text-align:left; border-bottom:1px solid #ddd;\"\u003eDescription\u003c\/th\u003e\n      \u003c\/tr\u003e\n    \u003c\/thead\u003e\n    \u003ctbody\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eConfiguration\u003c\/td\u003e\n        \u003ctd\u003eInline‑4 4‑Stroke, typically EFI; mechanical or drive‑by‑wire controls depending on year.\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eCommon Models\u003c\/td\u003e\n        \u003ctd\u003eGeneral‑purpose 25–115 HP 4‑Stroke models for fishing and runabouts.\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eAdvantages\u003c\/td\u003e\n        \u003ctd\u003eBalanced performance, low emissions, good mid‑range torque and economy.\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eNotes\u003c\/td\u003e\n        \u003ctd\u003eFuel filter type (inline vs. canister), anode layout, and thermostat ratings differ by model year and gearcase.\u003c\/td\u003e\n      \u003c\/tr\u003e\n    \u003c\/tbody\u003e\n  \u003c\/table\u003e\n\n  \u003ch3\u003eLarge Outboards\u003c\/h3\u003e\n  \u003ctable style=\"width:100%; max-width:900px; border-collapse:collapse;\"\u003e\n    \u003cthead\u003e\n      \u003ctr\u003e\n        \u003cth style=\"text-align:left; border-bottom:1px solid #ddd;\"\u003eFeature\u003c\/th\u003e\n        \u003cth style=\"text-align:left; border-bottom:1px solid #ddd;\"\u003eDescription\u003c\/th\u003e\n      \u003c\/tr\u003e\n    \u003c\/thead\u003e\n    \u003ctbody\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eConfiguration\u003c\/td\u003e\n        \u003ctd\u003eV6\/V8 4‑Stroke, EFI; digital throttle\/shift on some variants.\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eCommon Models\u003c\/td\u003e\n        \u003ctd\u003eHigh‑output 150–300+ HP 4‑Stroke models for offshore and heavy hulls.\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eAdvantages\u003c\/td\u003e\n        \u003ctd\u003eStrong top‑end power, refined NVH, advanced corrosion protection systems.\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eNotes\u003c\/td\u003e\n        \u003ctd\u003eMultiple thermostats, larger gearcases, and model‑specific anodes\/impellers; confirm by model code and serial.\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\"\u003e\n  \u003ch2\u003eRoutine Maintenance \u0026amp; Service Parts\u003c\/h2\u003e\n  \u003cp\u003eIntervals below are typical guidelines for 4‑Stroke outboards under normal use. Always follow your engine’s official service manual for exact procedures and schedules.\u003c\/p\u003e\n  \u003ctable style=\"width:100%; max-width:1000px; border-collapse:collapse;\"\u003e\n    \u003cthead\u003e\n      \u003ctr\u003e\n        \u003cth style=\"text-align:left; border-bottom:1px solid #ddd;\"\u003eItem\u003c\/th\u003e\n        \u003cth style=\"text-align:left; border-bottom:1px solid #ddd;\"\u003eInterval*\u003c\/th\u003e\n        \u003cth style=\"text-align:left; border-bottom:1px solid #ddd;\"\u003eRemarks\u003c\/th\u003e\n        \u003cth style=\"text-align:left; border-bottom:1px solid #ddd;\"\u003eParts Link\u003c\/th\u003e\n      \u003c\/tr\u003e\n    \u003c\/thead\u003e\n    \u003ctbody\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eEngine oil + oil filter\u003c\/td\u003e\n        \u003ctd\u003eInitial 20 hrs, then every 100 hrs or annually\u003c\/td\u003e\n        \u003ctd\u003eUse marine‑grade FC‑W oil; replace crush washer on drain plug if required.\u003c\/td\u003e\n        \u003ctd\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\u003eGear oil (lower unit)\u003c\/td\u003e\n        \u003ctd\u003eEvery 100 hrs or annually\u003c\/td\u003e\n        \u003ctd\u003eInspect for water intrusion and metal on magnetic drain plug.\u003c\/td\u003e\n        \u003ctd\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\u003eSpark plugs\u003c\/td\u003e\n        \u003ctd\u003eInspect every 100 hrs; replace 200–300 hrs (usage dependent)\u003c\/td\u003e\n        \u003ctd\u003eVerify correct plug type and gap for your model.\u003c\/td\u003e\n        \u003ctd\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\u003eFuel filter \/ water‑separating filter\u003c\/td\u003e\n        \u003ctd\u003eEvery 100 hrs or annually\u003c\/td\u003e\n        \u003ctd\u003eReplace more often with ethanol fuel or dirty fuel sources.\u003c\/td\u003e\n        \u003ctd\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\u003eWater pump impeller\/kit\u003c\/td\u003e\n        \u003ctd\u003eEvery 200 hrs or 2 seasons (inspect annually)\u003c\/td\u003e\n        \u003ctd\u003eShorten interval for sandy\/silty waters or weak tell‑tale stream.\u003c\/td\u003e\n        \u003ctd\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\u003eAnodes (sacrificial)\u003c\/td\u003e\n        \u003ctd\u003eInspect every 50 hrs; replace when 50% depleted\u003c\/td\u003e\n        \u003ctd\u003eUse the correct material for your water (aluminum\/brackish, magnesium\/fresh, zinc\/salt).\u003c\/td\u003e\n        \u003ctd\u003e\u003ca href=\"https:\/\/seasierra.com\/collections\/anodes\"\u003eAnodes\u003c\/a\u003e\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eAir filter \/ intake screen (if equipped)\u003c\/td\u003e\n        \u003ctd\u003eInspect 100 hrs; replace as needed\u003c\/td\u003e\n        \u003ctd\u003eMany outboards use intake screens rather than paper filters; clean per manual.\u003c\/td\u003e\n        \u003ctd\u003e\u003ca href=\"https:\/\/seasierra.com\/collections\/air-filters\"\u003eAir Filters\u003c\/a\u003e\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eCharging\/alternator check\u003c\/td\u003e\n        \u003ctd\u003eTest annually\u003c\/td\u003e\n        \u003ctd\u003eMeasure battery voltage at idle and cruise RPM; inspect wiring and grounds.\u003c\/td\u003e\n        \u003ctd\u003e\u003ca href=\"https:\/\/seasierra.com\/collections\/alternators\"\u003eAlternators\u003c\/a\u003e\u003c\/td\u003e\n      \u003c\/tr\u003e\n    \u003c\/tbody\u003e\n  \u003c\/table\u003e\n  \u003cp style=\"font-size:12px; color:#555;\"\u003e*Intervals are general recommendations. Always confirm with your engine’s specific service schedule.\u003c\/p\u003e\n\u003c\/section\u003e\n\n\u003csection id=\"common-parts\"\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-pumps\"\u003eWater Pumps\u003c\/a\u003e and \u003ca href=\"https:\/\/seasierra.com\/collections\/impellers\"\u003eImpellers\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 and \u003ca href=\"https:\/\/seasierra.com\/collections\/starters\"\u003eStarters\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\u003ePropulsion – \u003ca href=\"https:\/\/seasierra.com\/collections\/propellers\"\u003ePropellers\u003c\/a\u003e\n\u003c\/li\u003e\n    \u003cli\u003eSealing \u0026amp; Gaskets – \u003ca href=\"https:\/\/seasierra.com\/collections\/gaskets\"\u003eGaskets\u003c\/a\u003e and \u003ca href=\"https:\/\/seasierra.com\/collections\/oil-seals\"\u003eOil Seals\u003c\/a\u003e\n\u003c\/li\u003e\n  \u003c\/ul\u003e\n\u003c\/section\u003e\n\n\u003csection id=\"troubleshooting\"\u003e\n  \u003ch2\u003eCommon Symptoms \u0026amp; Quick Checks\u003c\/h2\u003e\n  \u003ctable style=\"width:100%; max-width:1000px; border-collapse:collapse;\"\u003e\n    \u003cthead\u003e\n      \u003ctr\u003e\n        \u003cth style=\"text-align:left; border-bottom:1px solid #ddd;\"\u003eSymptom\u003c\/th\u003e\n        \u003cth style=\"text-align:left; border-bottom:1px solid #ddd;\"\u003eCheck First\u003c\/th\u003e\n        \u003cth style=\"text-align:left; border-bottom:1px solid #ddd;\"\u003eRelated Parts\u003c\/th\u003e\n      \u003c\/tr\u003e\n    \u003c\/thead\u003e\n    \u003ctbody\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eWeak tell‑tale stream or overheat alarm\u003c\/td\u003e\n        \u003ctd\u003eInspect intake screens for blockage; verify impeller condition; test thermostat operation.\u003c\/td\u003e\n        \u003ctd\u003eWater pump kit\/impeller, gaskets, intake screen, thermostat.\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003ePoor acceleration or power loss\u003c\/td\u003e\n        \u003ctd\u003eCheck prop condition\/pitch, fuel quality, and filter restriction; inspect spark plugs.\u003c\/td\u003e\n        \u003ctd\u003ePropellers, fuel filters, spark plugs, injectors.\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eHard starting or rough idle\u003c\/td\u003e\n        \u003ctd\u003eTest battery voltage and cranking speed; inspect plugs; look for water in fuel.\u003c\/td\u003e\n        \u003ctd\u003eStarters, spark plugs, fuel filters, injectors.\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eGearcase noise or metal in gear oil\u003c\/td\u003e\n        \u003ctd\u003eDrain and inspect gear lube; check magnet; verify prop shaft for fishing line damage.\u003c\/td\u003e\n        \u003ctd\u003eLower unit seal kits, bearings, washers, propellers.\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eLow charging voltage\u003c\/td\u003e\n        \u003ctd\u003eVerify alternator output and regulator\/rectifier; inspect connectors and grounds.\u003c\/td\u003e\n        \u003ctd\u003eAlternators, rectifiers, electrical items.\u003c\/td\u003e\n      \u003c\/tr\u003e\n    \u003c\/tbody\u003e\n  \u003c\/table\u003e\n\u003c\/section\u003e\n\n\u003csection id=\"faq\"\u003e\n  \u003ch2\u003eFAQs\u003c\/h2\u003e\n  \u003cdetails\u003e\n    \u003csummary\u003eAre parts interchangeable between different years or platforms?\u003c\/summary\u003e\n    \u003cp\u003eSome service items cross over, but many 4‑Stroke parts vary by model code, serial range, and gearcase. Always confirm with the exact model and serial to avoid fitment issues.\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\u003eInspect annually and replace every 2 seasons or ~200 hours, sooner if you run in sandy or silty water or notice a weak cooling stream.\u003c\/p\u003e\n  \u003c\/details\u003e\n  \u003cdetails\u003e\n    \u003csummary\u003eHow often should I change gear oil?\u003c\/summary\u003e\n    \u003cp\u003eTypically every 100 hours or annually. If the oil appears milky or you see metal on the drain plug magnet, service immediately and inspect seals.\u003c\/p\u003e\n  \u003c\/details\u003e\n  \u003cdetails\u003e\n    \u003csummary\u003eWhat information do you need to confirm part compatibility?\u003c\/summary\u003e\n    \u003cp\u003ePlease provide the full model code, serial number, shaft length, and any visible casting numbers from the part. A clear photo of the nameplate is 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 #eee;\"\u003e\n  \u003cp\u003eReady to find the right parts? Browse our collections by brand, horsepower, and model to service your 4‑Stroke outboard with confidence.\u003c\/p\u003e\n  \u003cp\u003e\u003ca href=\"https:\/\/seasierra.com\/collections\/service-maintenance-kits\" style=\"display:inline-block; padding:10px 14px; border:1px solid #0a5; border-radius:6px; text-decoration:none;\"\u003eStart With Service \u0026amp; Maintenance Kits\u003c\/a\u003e\u003c\/p\u003e\n  \u003cp style=\"font-size:12px; color:#555;\"\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":"boat-pwc-registration-decals-fits-boats-pwcs-replaces-generic-registration-stickers","title":"Boat and PWC Registration Decals – 3-Inch Marine Vinyl Letters and Numbers","description":"\u003csection\u003e\n    \u003ch2\u003eProduct Details\u003c\/h2\u003e\n    \u003cp\u003eThese \u003cstrong\u003eBoat Registration Numbers and Letters\u003c\/strong\u003e are designed for boats and personal watercraft (PWC). The individual decals are made from marine-grade vinyl and are intended for application to clean, smooth, non-porous surfaces. When applied correctly, the 3-inch character height is suitable for common recreational vessel registration-number requirements; always verify the specific color, spacing, placement, and visibility rules that apply in your jurisdiction.\u003c\/p\u003e\n    \u003cul\u003e\n        \u003cli\u003ePeel-and-apply installation on most smooth, clean surfaces such as gel coat, fiberglass, painted aluminum, metal, wood, and plastic.\u003c\/li\u003e\n        \u003cli\u003eMarine-grade vinyl provides resistance to UV exposure, water, and normal marine conditions.\u003c\/li\u003e\n        \u003cli\u003eIndividual die-cut characters allow flexible layout and spacing for vessel identification.\u003c\/li\u003e\n        \u003cli\u003eSuitable for use on hard, smooth, non-porous surfaces; not recommended for inflatable PVC or Hypalon boats.\u003c\/li\u003e\n    \u003c\/ul\u003e\n\n    \u003ch2\u003eTechnical Specs\u003c\/h2\u003e\n    \u003cdl\u003e\n        \u003cdt\u003eProduct Type\u003c\/dt\u003e\n        \u003cdd\u003eBoat and PWC registration numbers and letters\u003c\/dd\u003e\n        \u003cdt\u003eMaterial\u003c\/dt\u003e\n        \u003cdd\u003eMarine-grade vinyl\u003c\/dd\u003e\n        \u003cdt\u003eCharacter Height\u003c\/dt\u003e\n        \u003cdd\u003e3 inches (76.2 mm)\u003c\/dd\u003e\n        \u003cdt\u003eAdhesive\u003c\/dt\u003e\n        \u003cdd\u003ePermanent waterproof adhesive\u003c\/dd\u003e\n        \u003cdt\u003eWeather Resistance\u003c\/dt\u003e\n        \u003cdd\u003eUV resistant and waterproof\u003c\/dd\u003e\n        \u003cdt\u003eChemical Resistance\u003c\/dt\u003e\n        \u003cdd\u003eResistant to normal exposure to fuel and outdoor conditions\u003c\/dd\u003e\n        \u003cdt\u003eColors Available\u003c\/dt\u003e\n        \u003cdd\u003eMultiple color options, including red, green, black, and white\u003c\/dd\u003e\n        \u003cdt\u003ePackage Contents\u003c\/dt\u003e\n        \u003cdd\u003e4 complete sets of letters A–Z and numbers 0–9\u003c\/dd\u003e\n        \u003cdt\u003eTotal Characters\u003c\/dt\u003e\n        \u003cdd\u003e144 individual characters\u003c\/dd\u003e\n        \u003cdt\u003eApplication\u003c\/dt\u003e\n        \u003cdd\u003ePeel and apply\u003c\/dd\u003e\n        \u003cdt\u003eCompatible Surfaces\u003c\/dt\u003e\n        \u003cdd\u003eGel coat, fiberglass, aluminum, painted metal, wood, and plastic\u003c\/dd\u003e\n        \u003cdt\u003eApproximate Width\u003c\/dt\u003e\n        \u003cdd\u003eApproximately 15 inches per properly spaced set\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;\"\u003e4 complete sets\u003c\/span\u003e of letters A–Z\u003c\/li\u003e\n        \u003cli\u003e\n\u003cspan style=\"color:#d0021b;\"\u003e4 complete sets\u003c\/span\u003e of numbers 0–9\u003c\/li\u003e\n    \u003c\/ul\u003e\n\n    \u003ch2\u003eInstallation Notes\u003c\/h2\u003e\n    \u003col\u003e\n        \u003cli\u003eClean and dry the application surface thoroughly. Remove dirt, wax, grease, and oils before application.\u003c\/li\u003e\n        \u003cli\u003ePlan and measure the layout on the hull before applying the characters. Confirm the required character height, spacing, contrast, and placement for your state or jurisdiction.\u003c\/li\u003e\n        \u003cli\u003eCarefully peel the backing from each individual character.\u003c\/li\u003e\n        \u003cli\u003eApply each decal one at a time according to the planned layout.\u003c\/li\u003e\n        \u003cli\u003ePress each character firmly from the center outward to remove air bubbles and promote a strong bond.\u003c\/li\u003e\n        \u003cli\u003eAllow the adhesive to set according to the conditions recommended for the material. Avoid applying decals to wet, waxed, heavily textured, or contaminated surfaces.\u003c\/li\u003e\n    \u003c\/ol\u003e\n    \u003cp\u003e\u003cstrong\u003eImportant:\u003c\/strong\u003e These are individual die-cut characters. They are not supplied as pre-spaced words or numbers on a single transfer-tape sheet. Some decal styles may be offered separately with a transparent outline or two-tone appearance.\u003c\/p\u003e\n\n    \u003ch2\u003eTroubleshooting and FAQ\u003c\/h2\u003e\n    \u003cdetails\u003e\n        \u003csummary\u003eAre these decals compliant with boating regulations?\u003c\/summary\u003e\n        \u003cp\u003eThe characters are 3 inches high, which is commonly used for recreational vessel registration numbers. Compliance also depends on the vessel, state or jurisdiction, character spacing, placement, contrast, and visibility. The vessel owner is responsible for confirming and following all applicable requirements before application.\u003c\/p\u003e\n    \u003c\/details\u003e\n    \u003cdetails\u003e\n        \u003csummary\u003eHow should I space the letters and numbers?\u003c\/summary\u003e\n        \u003cp\u003eRegistration-number formats and spacing rules vary by jurisdiction. A commonly used arrangement separates the letter and number groups with a space approximately equal to one character width, such as \u003cstrong\u003eFL 1234 AB\u003c\/strong\u003e. Measure and plan the complete layout before applying the decals, and follow the requirements for your vessel’s registration location.\u003c\/p\u003e\n    \u003c\/details\u003e\n    \u003cdetails\u003e\n        \u003csummary\u003eWhat design options are available?\u003c\/summary\u003e\n        \u003cp\u003eAvailable styles may include \u003cstrong\u003eSolid Color\u003c\/strong\u003e for a classic single-color appearance, \u003cstrong\u003eTransparent with Outline\u003c\/strong\u003e for a clear center with an outlined edge, and \u003cstrong\u003eTwo-Tone\u003c\/strong\u003e for a combination of colors. Confirm the selected color and style before ordering.\u003c\/p\u003e\n    \u003c\/details\u003e\n    \u003cdetails\u003e\n        \u003csummary\u003eCan the decals be removed?\u003c\/summary\u003e\n        \u003cp\u003eThe decals use permanent adhesive for long-term outdoor use. Removal may require gentle heat from a hairdryer or heat gun and a plastic scraper. Adhesive remover may be needed for residue. Work carefully to avoid damaging the underlying finish.\u003c\/p\u003e\n    \u003c\/details\u003e\n    \u003cdetails\u003e\n        \u003csummary\u003eWill these decals stick to an inflatable boat?\u003c\/summary\u003e\n        \u003cp\u003eThese decals are intended for hard, smooth, non-porous surfaces such as fiberglass, gel coat, and painted aluminum. They are not recommended for inflatable boats made from PVC or Hypalon because flexibility, texture, and surface treatments can prevent a durable bond. Stencils and specialized marine paint may be more suitable for inflatable materials.\u003c\/p\u003e\n    \u003c\/details\u003e\n    \u003cdetails\u003e\n        \u003csummary\u003eIs this an OEM part?\u003c\/summary\u003e\n        \u003cp\u003eThis is an aftermarket registration-decal product, not an OEM boat or PWC component. It is intended for vessel identification and is not a mechanical replacement part.\u003c\/p\u003e\n    \u003c\/details\u003e\n    \u003cdetails\u003e\n        \u003csummary\u003eWhat are the shipping speed and cost?\u003c\/summary\u003e\n        \u003cp\u003eShipping options, delivery estimates, and costs depend on the destination and are shown at checkout. Expedited services may be available for eligible locations.\u003c\/p\u003e\n    \u003c\/details\u003e\n    \u003cdetails\u003e\n        \u003csummary\u003eWhat should I do if a decal is damaged or does not apply correctly?\u003c\/summary\u003e\n        \u003cp\u003eStop application if the surface is dirty, wet, waxed, or otherwise unsuitable. Keep the unused characters and packaging, and contact support with order details and photographs if there is a product or fulfillment issue.\u003c\/p\u003e\n    \u003c\/details\u003e\n\n    \u003ch2\u003eSafety and Important Information\u003c\/h2\u003e\n    \u003cul\u003e\n        \u003cli\u003eConfirm the required registration-number size, color contrast, spacing, and placement for your vessel before installation.\u003c\/li\u003e\n        \u003cli\u003eApply only to a clean, dry, smooth surface that is compatible with permanent vinyl adhesive.\u003c\/li\u003e\n        \u003cli\u003eDo not apply to inflatable materials unless the surface manufacturer specifically confirms compatibility.\u003c\/li\u003e\n        \u003cli\u003eUse care when removing decals with heat, scrapers, or adhesive remover to prevent damage to the underlying finish.\u003c\/li\u003e\n    \u003c\/ul\u003e\n\n    \u003ch2\u003eAbout Sea Sierra\u003c\/h2\u003e\n    \u003cul\u003e\n        \u003cli\u003e\n\u003cstrong\u003eMarine-Focused Products\u003c\/strong\u003e — Practical products selected for use in boating and personal-watercraft applications.\u003c\/li\u003e\n        \u003cli\u003e\n\u003cstrong\u003eConvenient Fulfillment\u003c\/strong\u003e — Shipping options and delivery estimates are provided for your destination at checkout.\u003c\/li\u003e\n        \u003cli\u003e\n\u003cstrong\u003eCustomer Support\u003c\/strong\u003e — Contact support if you need help with product questions or an order issue.\u003c\/li\u003e\n    \u003c\/ul\u003e\n\u003c\/section\u003e","brand":"SeaSierra","offers":[{"title":"Default Title","offer_id":50717893656891,"sku":"Green001-QM","price":19.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0826\/8673\/8747\/files\/Green001-QM.png?v=1762937613"},{"product_id":"whale-tail-hydrofoil-stabilizer-fits-outboard-motors-stern-drives-40-300-hp-replaces-fo2003","title":"Whale Tail Hydrofoil Stabilizer for 40–300 HP Outboard Motors and Stern Drives","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 marine-grade reinforced PA66 nylon \u003cstrong\u003eWhale Tail Hydrofoil Stabilizer\u003c\/strong\u003e is designed for many 40–300 HP outboard motors and stern drives. By adding hydrodynamic lift at the stern, it can help improve low-speed handling, reduce porpoising, shorten time to plane, and help the boat remain on plane at lower speeds.\u003c\/p\u003e\n\u003cp\u003eThis is an aftermarket hydrofoil stabilizer referenced in some listings as a replacement for FO2003 and as a Whale Tail-style hydrofoil. Confirm the dimensions, mounting area, engine or drive configuration, and listed exceptions before ordering.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eDrill-and-bolt installation on the anti-cavitation plate; mounting hardware and a drill bit are included.\u003c\/li\u003e\n  \u003cli\u003eMade from reinforced, marine-grade PA66 nylon for strength, impact resistance, and corrosion resistance.\u003c\/li\u003e\n  \u003cli\u003eThe curved hydrofoil profile is intended to improve stern lift while helping manage drag and propeller-area turbulence.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2\u003ePart Number References\u003c\/h2\u003e\n\u003cp\u003eThe references below are aftermarket or listing references and should not be treated as proof of fitment by themselves. Always compare the product dimensions and application requirements with your equipment.\u003c\/p\u003e\n\u003cdiv class=\"ss-table-wrap\"\u003e\n  \u003ctable class=\"ss-table\" aria-label=\"Part Number References\"\u003e\n    \u003cthead\u003e\n      \u003ctr\u003e\n        \u003cth\u003eReference\u003c\/th\u003e\n        \u003cth\u003eNumber or Description\u003c\/th\u003e\n      \u003c\/tr\u003e\n    \u003c\/thead\u003e\n    \u003ctbody\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eAftermarket reference\u003c\/td\u003e\n        \u003ctd\u003eFO2003\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eProduct style\u003c\/td\u003e\n        \u003ctd\u003eWhale Tail Hydrofoil Stabilizer\u003c\/td\u003e\n      \u003c\/tr\u003e\n    \u003c\/tbody\u003e\n  \u003c\/table\u003e\n\u003c\/div\u003e\n\n\u003ch2\u003eEngine and Drive Compatibility\u003c\/h2\u003e\n\u003cp\u003eApplication depends on the shape and available mounting area of the anti-cavitation plate or drive. The following information describes the intended application range and important exclusions noted for this style of hydrofoil; it does not replace a dimensional fit check.\u003c\/p\u003e\n\u003cdiv class=\"ss-table-wrap\"\u003e\n  \u003ctable class=\"ss-table\" aria-label=\"Engine and Drive Compatibility\"\u003e\n    \u003cthead\u003e\n      \u003ctr\u003e\n        \u003cth\u003eBrand or Application\u003c\/th\u003e\n        \u003cth\u003eCompatibility\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\u003eGeneral application\u003c\/td\u003e\n        \u003ctd\u003eMany 40–300 HP outboard motors and stern drives\u003c\/td\u003e\n        \u003ctd\u003eConfirm clearance, mounting surface, dimensions, and hardware requirements before installation.\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eVolvo Penta\u003c\/td\u003e\n        \u003ctd\u003eSX-A, DPS, DPR, DPH, and 280\/290 series applications may be suitable\u003c\/td\u003e\n        \u003ctd\u003eSome installations may require longer bolts and 1-inch fender washers. Not recommended for Volvo Ocean Series XDP applications.\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eMercury\u003c\/td\u003e\n        \u003ctd\u003eMany 40–300 HP applications\u003c\/td\u003e\n        \u003ctd\u003eNot recommended for Mercury 4-Stroke 40, 50, or 60 HP models and not for Mercury Bravo II.\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eHonda\u003c\/td\u003e\n        \u003ctd\u003eMany 40–200 HP applications\u003c\/td\u003e\n        \u003ctd\u003eNot recommended for applications above 200 HP.\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eYamaha\u003c\/td\u003e\n        \u003ctd\u003eMany 40–300 HP applications\u003c\/td\u003e\n        \u003ctd\u003eNot recommended for 350 HP applications.\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\u003cdl\u003e\n  \u003cdt\u003eProduct Type\u003c\/dt\u003e\n  \u003cdd\u003eHydrofoil stabilizer\u003c\/dd\u003e\n  \u003cdt\u003eInstallation\u003c\/dt\u003e\n  \u003cdd\u003eFour-bolt installation; drilling required\u003c\/dd\u003e\n  \u003cdt\u003eMounting Location\u003c\/dt\u003e\n  \u003cdd\u003eAnti-cavitation plate or compatible stern-drive mounting surface\u003c\/dd\u003e\n  \u003cdt\u003eMaterial\u003c\/dt\u003e\n  \u003cdd\u003eReinforced PA66 nylon, marine-grade plastic\u003c\/dd\u003e\n  \u003cdt\u003eColor\u003c\/dt\u003e\n  \u003cdd\u003eBlue, silver, or red depending on the selected model or available version\u003c\/dd\u003e\n  \u003cdt\u003eDimensions\u003c\/dt\u003e\n  \u003cdd\u003eApproximately 17 × 14.4 inches (432 × 366 mm)\u003c\/dd\u003e\n  \u003cdt\u003eWeight\u003c\/dt\u003e\n  \u003cdd\u003eApproximately 1.72 kg (3.79 lb)\u003c\/dd\u003e\n  \u003cdt\u003eFitting Type\u003c\/dt\u003e\n  \u003cdd\u003eDrill and bolt\u003c\/dd\u003e\n  \u003cdt\u003eHydrofoil Profile\u003c\/dt\u003e\n  \u003cdd\u003eCurved profile designed to provide stern lift and help reduce porpoising\u003c\/dd\u003e\n\u003c\/dl\u003e\n\n\u003ch2\u003eWhat's in the Box\u003c\/h2\u003e\n\u003cul\u003e\n  \u003cli\u003e1 × Hydrofoil stabilizer\u003c\/li\u003e\n  \u003cli\u003e4 × Sets of stainless-steel screws, washers, and nuts\u003c\/li\u003e\n  \u003cli\u003e1 × 6.5 mm drill bit\u003c\/li\u003e\n  \u003cli\u003e1 × Installation instruction sheet\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2\u003eInstallation Notes\u003c\/h2\u003e\n\u003col\u003e\n  \u003cli\u003eFor safety, disconnect the engine battery before beginning installation.\u003c\/li\u003e\n  \u003cli\u003eCenter the hydrofoil on the anti-cavitation plate or compatible drive mounting surface. Position it as far back as practical without interfering with propeller movement or steering components.\u003c\/li\u003e\n  \u003cli\u003eUse the hydrofoil mounting holes as a template and mark the four drilling points.\u003c\/li\u003e\n  \u003cli\u003eRemove the hydrofoil and carefully drill the marked holes with the included 6.5 mm drill bit, provided the plate thickness and material are suitable for drilling.\u003c\/li\u003e\n  \u003cli\u003ePlace the hydrofoil on the plate and align it with the drilled holes.\u003c\/li\u003e\n  \u003cli\u003eInsert the stainless-steel bolts from the top and secure them underneath with the washers and nuts.\u003c\/li\u003e\n  \u003cli\u003eTighten the fasteners evenly and securely. Do not overtighten, as this may damage the plate or the hydrofoil.\u003c\/li\u003e\n  \u003cli\u003eReconnect the battery and test the boat at low speed in a safe, open-water area. Check the installation again after the initial test run.\u003c\/li\u003e\n\u003c\/ol\u003e\n\n\u003ch2\u003eTroubleshooting and FAQ\u003c\/h2\u003e\n\u003cdetails\u003e\n  \u003csummary\u003eWill this hydrofoil fit my specific engine or drive?\u003c\/summary\u003e\n  \u003cp\u003eThis stabilizer is intended for many 40–300 HP outboard motors and stern drives, but fitment depends on the plate or drive geometry, available mounting area, clearance, and the exclusions listed above. Compare the dimensions and installation requirements with your equipment before ordering.\u003c\/p\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n  \u003csummary\u003eDo I have to drill holes in the anti-cavitation plate?\u003c\/summary\u003e\n  \u003cp\u003eYes. This model uses a four-bolt installation and requires four holes to be drilled in a suitable mounting surface. If you are not certain that the plate can be drilled safely, consult a qualified marine technician.\u003c\/p\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n  \u003csummary\u003eHow can a hydrofoil improve performance?\u003c\/summary\u003e\n  \u003cp\u003eThe hydrofoil adds hydrodynamic lift to the stern. Depending on the boat and setup, this may help the boat reach plane sooner, stay on plane at lower speeds, improve low-speed handling, and reduce bow bouncing or porpoising.\u003c\/p\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n  \u003csummary\u003eWill this reduce my boat's top speed?\u003c\/summary\u003e\n  \u003cp\u003eResults vary by boat, engine, propeller, loading, and installation. A hydrofoil may change handling and speed characteristics, and some setups may experience a small reduction in top speed because of added drag. Test the boat carefully after installation.\u003c\/p\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n  \u003csummary\u003eWhat is the benefit of reinforced PA66 nylon?\u003c\/summary\u003e\n  \u003cp\u003eReinforced PA66 nylon combines stiffness, impact resistance, and corrosion resistance. It is intended to provide a durable alternative to ordinary unreinforced plastic in a marine environment.\u003c\/p\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n  \u003csummary\u003eIs this an OEM part?\u003c\/summary\u003e\n  \u003cp\u003eNo. This listing is for an aftermarket hydrofoil stabilizer. The FO2003 reference is provided as an aftermarket reference only and does not, by itself, establish OEM manufacture or universal interchangeability.\u003c\/p\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n  \u003csummary\u003eHow should I confirm fitment before ordering?\u003c\/summary\u003e\n  \u003cp\u003eCheck the available mounting area, overall dimensions, anti-cavitation plate or drive shape, propeller and steering clearance, engine horsepower, and the model-specific exclusions. If any measurement or application detail differs, do not proceed without professional confirmation.\u003c\/p\u003e\n\u003c\/details\u003e\n\n\u003ch2\u003eSafety and Important Information\u003c\/h2\u003e\n\u003cul\u003e\n  \u003cli\u003eVerify the dimensions, mounting surface, clearances, and application notes against your equipment before purchase.\u003c\/li\u003e\n  \u003cli\u003eThis product requires drilling and bolting; professional marine installation is recommended when you are not experienced with structural or engine-related work.\u003c\/li\u003e\n  \u003cli\u003eInspect all fasteners and the hydrofoil after the first test run and periodically during use.\u003c\/li\u003e\n  \u003cli\u003eDo not operate the boat if the hydrofoil is loose, cracked, damaged, or interfering with the propeller, steering, or trim system.\u003c\/li\u003e\n  \u003cli\u003eThis is an aftermarket replacement product, not an OEM component.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2\u003eAbout Sea Sierra\u003c\/h2\u003e\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003ePro-Grade Standards\u003c\/strong\u003e — We supply marine parts selected for dependable materials and real-world use.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eManufacturer-Direct Value\u003c\/strong\u003e — We aim to provide practical replacement solutions with clear product information.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eSupport-Focused Service\u003c\/strong\u003e — Confirm your application details before ordering and contact support if you need help reviewing product measurements or installation requirements.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/section\u003e","brand":"SeaSierra","offers":[{"title":"Default Title","offer_id":50718235459899,"sku":"WV-JALU-N3EB","price":64.89,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0826\/8673\/8747\/files\/WV-JALU-N3EB.png?v=1762958052"}],"url":"https:\/\/seasierra.com\/collections\/4-stroke-marine-engine-parts.oembed","provider":"SeaSierra","version":"1.0","type":"link"}