{"product_id":"straight-screw-plug-kit-fits-yamaha-40hp-300hp-replaces-688-45341-90340-08002-00-90430-08020","title":"Straight Screw Plug Kit – Fits Yamaha 40HP-300HP (Replaces 688-45341, 90340-08002-00, 90430-08020)","description":"\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 \u003cstrong\u003eStraight Screw Plug Kit\u003c\/strong\u003e is designed for Yamaha outboard engines ranging from 40HP to 300HP. It services most but not all engines in this horsepower range, making it essential to buy by part number rather than engine horsepower alone. This comprehensive drain plug kit ensures reliable lower unit maintenance across a wide range of Yamaha models.\u003c\/p\u003e\n\u003cp\u003eThis kit directly replaces OEM part numbers 688-45341, 90340-08002-00, and 90430-08020, providing a cost-effective aftermarket solution for lower unit servicing.\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eComplete drain plug assembly with gaskets included\u003c\/li\u003e\n\u003cli\u003eSuitable for routine lower unit oil changes and maintenance\u003c\/li\u003e\n\u003cli\u003eApplication-critical: always verify part number against your engine before purchase\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2\u003ePart Number Matrix\u003c\/h2\u003e\n\u003cp\u003eUse this matrix to confirm equivalent references across OEM and aftermarket.\u003c\/p\u003e\n\u003cdiv class=\"ss-table-wrap\"\u003e\n  \u003ctable class=\"ss-table\" aria-label=\"Part Number Matrix\"\u003e\n    \u003cthead\u003e\n      \u003ctr\u003e\n        \u003cth\u003eBrand\u003c\/th\u003e\n        \u003cth\u003ePart 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\u003eYamaha\u003c\/td\u003e\n        \u003ctd\u003e688-45341-10-00\u003c\/td\u003e\n        \u003ctd\u003eLower Unit Drain Plug\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eYamaha\u003c\/td\u003e\n        \u003ctd\u003e688-45341\u003c\/td\u003e\n        \u003ctd\u003eLower Unit Drain Plug\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eYamaha\u003c\/td\u003e\n        \u003ctd\u003e90340-08002-00\u003c\/td\u003e\n        \u003ctd\u003eStraight Screw Plug\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eYamaha\u003c\/td\u003e\n        \u003ctd\u003e90340-08002\u003c\/td\u003e\n        \u003ctd\u003eStraight Screw Plug\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eYamaha\u003c\/td\u003e\n        \u003ctd\u003e90430-08020\u003c\/td\u003e\n        \u003ctd\u003eLower Unit Oil Drain Gasket\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eYamaha\u003c\/td\u003e\n        \u003ctd\u003e90430-08003\u003c\/td\u003e\n        \u003ctd\u003eGasket\u003c\/td\u003e\n      \u003c\/tr\u003e\n    \u003c\/tbody\u003e\n  \u003c\/table\u003e\n\u003c\/div\u003e\n\n\u003ch2\u003eEngine \u0026amp; Model Compatibility\u003c\/h2\u003e\n\u003cp\u003eConfirm your engine model\/year in the table below.\u003c\/p\u003e\n\u003cdiv class=\"ss-table-wrap\"\u003e\n  \u003ctable class=\"ss-table\" aria-label=\"Engine and Model Compatibility\"\u003e\n    \u003cthead\u003e\n      \u003ctr\u003e\n        \u003cth\u003eBrand\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\u003eYamaha\u003c\/td\u003e\n        \u003ctd\u003e40HP–300HP\u003c\/td\u003e\n        \u003ctd\u003eFits most but not all engines in this range. Buy by part number, not horsepower.\u003c\/td\u003e\n      \u003c\/tr\u003e\n    \u003c\/tbody\u003e\n  \u003c\/table\u003e\n\u003c\/div\u003e\n\n\u003ch2\u003eTechnical Specs\u003c\/h2\u003e\n\u003cdl\u003e\n  \u003cdt\u003eProduct Type\u003c\/dt\u003e\n  \u003cdd\u003eStraight Screw Plug Kit\u003c\/dd\u003e\n  \u003cdt\u003ePrimary Application\u003c\/dt\u003e\n  \u003cdd\u003eLower unit drain and fill service\u003c\/dd\u003e\n  \u003cdt\u003eCompatibility\u003c\/dt\u003e\n  \u003cdd\u003eYamaha outboards 40HP–300HP (verify part number)\u003c\/dd\u003e\n  \u003cdt\u003eKit Components\u003c\/dt\u003e\n  \u003cdd\u003eDrain plug, screw plug, and gaskets\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\u003cstrong\u003e1 ×\u003c\/strong\u003e Lower Unit Drain Plug (688-45341)\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003e1 ×\u003c\/strong\u003e Straight Screw Plug (90340-08002)\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003e2 ×\u003c\/strong\u003e Lower Unit Oil Drain Gasket (90430-08020)\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2\u003eInstallation Notes\u003c\/h2\u003e\n\u003col\u003e\n  \u003cli\u003ePosition the outboard upright and allow the lower unit to drain completely if performing an oil change.\u003c\/li\u003e\n  \u003cli\u003eRemove the old drain plug(s) and inspect threads for damage or corrosion.\u003c\/li\u003e\n  \u003cli\u003eClean the drain hole area thoroughly to remove old gasket material and debris.\u003c\/li\u003e\n  \u003cli\u003eInstall a new gasket onto the drain plug. Do not reuse old gaskets.\u003c\/li\u003e\n  \u003cli\u003eThread the drain plug by hand first to avoid cross-threading.\u003c\/li\u003e\n  \u003cli\u003eTighten to manufacturer-specified torque using a calibrated torque wrench.\u003c\/li\u003e\n  \u003cli\u003eRefill the lower unit with the correct type and quantity of gear oil per your service manual.\u003c\/li\u003e\n  \u003cli\u003eCheck for leaks after installation and during the first few hours of operation.\u003c\/li\u003e\n\u003c\/ol\u003e\n\n\u003ch2\u003eTroubleshooting \u0026amp; FAQ\u003c\/h2\u003e\n\u003cdetails\u003e\n  \u003csummary\u003eHow do I know if this kit fits my Yamaha outboard?\u003c\/summary\u003e\n  \u003cp\u003eCross-reference the OEM part numbers (688-45341, 90340-08002-00, 90430-08020) with your engine's parts diagram or service manual. Do not rely solely on horsepower rating, as some engines in the 40–300HP range may use different plugs.\u003c\/p\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n  \u003csummary\u003eCan I reuse the old gaskets?\u003c\/summary\u003e\n  \u003cp\u003eNo. Always replace gaskets during lower unit service to ensure a proper seal and prevent leaks. This kit includes two new gaskets.\u003c\/p\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n  \u003csummary\u003eWhat torque setting should I use for the drain plugs?\u003c\/summary\u003e\n  \u003cp\u003eRefer to your Yamaha service manual for the exact torque specification. Over-tightening can strip threads or crack the lower unit housing; under-tightening may cause leaks.\u003c\/p\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n  \u003csummary\u003eHow often should I replace the drain plugs and gaskets?\u003c\/summary\u003e\n  \u003cp\u003eGaskets should be replaced at every lower unit oil change. Drain plugs should be inspected each time and replaced if threads are damaged, corroded, or if the magnetic tip (if applicable) is excessively worn.\u003c\/p\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n  \u003csummary\u003eWhat are signs that my lower unit drain plug is failing?\u003c\/summary\u003e\n  \u003cp\u003eVisible gear oil leaks around the plug, difficulty removing or installing the plug, stripped threads, or metal shavings on the magnetic tip beyond normal accumulation all indicate replacement is needed.\u003c\/p\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n  \u003csummary\u003eIs there a difference between the two plugs in this kit?\u003c\/summary\u003e\n  \u003cp\u003eYes. The kit includes one lower unit drain plug (688-45341) and one straight screw plug (90340-08002). Each serves a specific location on the lower unit. Install each in its correct position as shown in your service manual.\u003c\/p\u003e\n\u003c\/details\u003e\n\n\u003ch2\u003eSafety \u0026amp; Important Info\u003c\/h2\u003e\n\u003cul\u003e\n  \u003cli\u003eVerify images\/specifications against your original part. If anything differs—even if your model appears compatible—do not purchase.\u003c\/li\u003e\n  \u003cli\u003eThis is an aftermarket replacement, not an OEM component.\u003c\/li\u003e\n  \u003cli\u003eProfessional installation is recommended for safety and performance.\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"SeaSierra","offers":[{"title":"Default Title","offer_id":51025914593595,"sku":"25GK072","price":16.14,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0826\/8673\/8747\/files\/12_dc075fea-549a-446d-a6a0-baf12000de29.jpg?v=1772975095","url":"https:\/\/seasierra.com\/products\/straight-screw-plug-kit-fits-yamaha-40hp-300hp-replaces-688-45341-90340-08002-00-90430-08020","provider":"SeaSierra","version":"1.0","type":"link"}