{"product_id":"new-aftermarket-yamaha-75-100hp-outboard-lower-unit-90-404-2-4-stroke","title":"New Aftermarket Yamaha 75-100HP Outboard Lower Unit 90-404 2-4-Stroke","description":"\u003ch2 data-end=\"336\" data-start=\"249\"\u003e\u003cstrong data-end=\"334\" data-start=\"253\"\u003eBrand New Yamaha 75–100HP Replacement Lower Unit (2\/4-Stroke | 1984–2017)\u003c\/strong\u003e\u003c\/h2\u003e\n\u003cp data-end=\"672\" data-start=\"338\"\u003eEnhance the performance of your \u003cstrong data-end=\"398\" data-start=\"370\"\u003eYamaha 75–100HP outboard\u003c\/strong\u003e with this \u003cstrong data-end=\"460\" data-start=\"409\"\u003ehigh-quality aftermarket replacement lower unit\u003c\/strong\u003e from \u003cstrong data-end=\"489\" data-start=\"466\"\u003eSEI Marine Products\u003c\/strong\u003e. Engineered for precision, durability, and a perfect OEM fit — this unit is the ideal choice for both 2-stroke and 4-stroke Yamaha outboards manufactured between \u003cstrong data-end=\"669\" data-start=\"652\"\u003e1984 and 2017\u003c\/strong\u003e.\u003c\/p\u003e\n\u003ch3 data-end=\"695\" data-start=\"674\"\u003e\u003cstrong data-end=\"695\" data-start=\"679\"\u003eKey Features\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cul data-end=\"1471\" data-start=\"696\"\u003e\n\u003cli data-end=\"851\" data-start=\"696\"\u003e\n\u003cp data-end=\"851\" data-start=\"698\"\u003e\u003cstrong data-end=\"744\" data-start=\"698\"\u003ePerfect Fit for Yamaha 75–100HP Outboards:\u003c\/strong\u003e Designed specifically to replace lower units on Yamaha F75, F80, F90, F100, and other compatible models.\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-end=\"988\" data-start=\"852\"\u003e\n\u003cp data-end=\"988\" data-start=\"854\"\u003e\u003cstrong data-end=\"883\" data-start=\"854\"\u003eWide Model Compatibility:\u003c\/strong\u003e Works seamlessly with \u003cstrong data-end=\"958\" data-start=\"906\"\u003eYamaha 2-stroke and 4-stroke engines (1984–2017)\u003c\/strong\u003e for versatile installation.\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-end=\"1182\" data-start=\"989\"\u003e\n\u003cp data-end=\"1182\" data-start=\"991\"\u003e\u003cstrong data-end=\"1032\" data-start=\"991\"\u003eMultiple Gear Ratios \u0026amp; Shaft Options:\u003c\/strong\u003e Available in \u003cstrong data-end=\"1077\" data-start=\"1046\"\u003e2.0:1 and 2.3:1 gear ratios\u003c\/strong\u003e and fits \u003cstrong data-end=\"1109\" data-start=\"1087\"\u003e20″ and 25″ shafts\u003c\/strong\u003e, ensuring optimal performance for your specific Yamaha 75–100HP motor.\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-end=\"1343\" data-start=\"1183\"\u003e\n\u003cp data-end=\"1343\" data-start=\"1185\"\u003e\u003cstrong data-end=\"1213\" data-start=\"1185\"\u003eDurable OEM-Like Finish:\u003c\/strong\u003e Finished in \u003cstrong data-end=\"1241\" data-start=\"1226\"\u003eblack paint\u003c\/strong\u003e, ready to install — can also be \u003cstrong data-end=\"1318\" data-start=\"1274\"\u003erepainted to match original Yamaha color\u003c\/strong\u003e for a custom OEM look.\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-end=\"1471\" data-start=\"1344\"\u003e\n\u003cp data-end=\"1471\" data-start=\"1346\"\u003e\u003cstrong data-end=\"1381\" data-start=\"1346\"\u003eReliable Performance Guarantee:\u003c\/strong\u003e Comes with a \u003cstrong data-end=\"1425\" data-start=\"1395\"\u003e3-Year Fault-Free Warranty\u003c\/strong\u003e, backed by SEI’s trusted quality assurance.\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003chr data-end=\"1476\" data-start=\"1473\"\u003e\n\u003ch3 data-end=\"1501\" data-start=\"1478\"\u003e\u003cstrong data-end=\"1501\" data-start=\"1483\"\u003eSpecifications\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cdiv class=\"_tableContainer_1rjym_1\"\u003e\n\u003cdiv class=\"group _tableWrapper_1rjym_13 flex w-fit flex-col-reverse\" tabindex=\"-1\"\u003e\n\u003ctable data-end=\"2097\" data-start=\"1503\" class=\"w-fit min-w-(--thread-content-width)\"\u003e\n\u003cthead data-end=\"1532\" data-start=\"1503\"\u003e\n\u003ctr data-end=\"1532\" data-start=\"1503\"\u003e\n\u003cth data-col-size=\"sm\" data-end=\"1517\" data-start=\"1503\"\u003e\u003cstrong data-end=\"1516\" data-start=\"1505\"\u003eFeature\u003c\/strong\u003e\u003c\/th\u003e\n\u003cth data-col-size=\"md\" data-end=\"1532\" data-start=\"1517\"\u003e\u003cstrong data-end=\"1530\" data-start=\"1519\"\u003eDetails\u003c\/strong\u003e\u003c\/th\u003e\n\u003c\/tr\u003e\n\u003c\/thead\u003e\n\u003ctbody data-end=\"2097\" data-start=\"1564\"\u003e\n\u003ctr data-end=\"1604\" data-start=\"1564\"\u003e\n\u003ctd data-col-size=\"sm\" data-end=\"1587\" data-start=\"1564\"\u003e\u003cstrong data-end=\"1586\" data-start=\"1566\"\u003eHorsepower Range\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd data-end=\"1604\" data-start=\"1587\" data-col-size=\"md\"\u003e75HP to 100HP\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr data-end=\"1646\" data-start=\"1605\"\u003e\n\u003ctd data-col-size=\"sm\" data-end=\"1623\" data-start=\"1605\"\u003e\u003cstrong data-end=\"1622\" data-start=\"1607\"\u003eStroke Type\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd data-end=\"1646\" data-start=\"1623\" data-col-size=\"md\"\u003e2-Stroke \u0026amp; 4-Stroke\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr data-end=\"1687\" data-start=\"1647\"\u003e\n\u003ctd data-col-size=\"sm\" data-end=\"1662\" data-start=\"1647\"\u003e\u003cstrong data-end=\"1661\" data-start=\"1649\"\u003eRotation\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd data-end=\"1687\" data-start=\"1662\" data-col-size=\"md\"\u003eStandard (Right-Hand)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr data-end=\"1743\" data-start=\"1688\"\u003e\n\u003ctd data-col-size=\"sm\" data-end=\"1706\" data-start=\"1688\"\u003e\u003cstrong data-end=\"1705\" data-start=\"1690\"\u003eGear Ratios\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd data-end=\"1743\" data-start=\"1706\" data-col-size=\"md\"\u003e2.0:1 and 2.3:1 (model dependent)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr data-end=\"1777\" data-start=\"1744\"\u003e\n\u003ctd data-col-size=\"sm\" data-end=\"1764\" data-start=\"1744\"\u003e\u003cstrong data-end=\"1763\" data-start=\"1746\"\u003eShaft Lengths\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd data-col-size=\"md\" data-end=\"1777\" data-start=\"1764\"\u003e20″ \u0026amp; 25″\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr data-end=\"1839\" data-start=\"1778\"\u003e\n\u003ctd data-col-size=\"sm\" data-end=\"1796\" data-start=\"1778\"\u003e\u003cstrong data-end=\"1795\" data-start=\"1780\"\u003ePaint Color\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd data-col-size=\"md\" data-end=\"1839\" data-start=\"1796\"\u003eBlack (Repaintable to match OEM finish)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr data-end=\"1931\" data-start=\"1840\"\u003e\n\u003ctd data-col-size=\"sm\" data-end=\"1858\" data-start=\"1840\"\u003e\u003cstrong data-end=\"1857\" data-start=\"1842\"\u003eFits Models\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd data-end=\"1931\" data-start=\"1858\" data-col-size=\"md\"\u003eF75, F80, F90, F100, 90TLR, E75, and others (see detailed list below)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr data-end=\"2015\" data-start=\"1932\"\u003e\n\u003ctd data-col-size=\"sm\" data-end=\"1949\" data-start=\"1932\"\u003e\u003cstrong data-end=\"1948\" data-start=\"1934\"\u003eExclusions\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd data-end=\"2015\" data-start=\"1949\" data-col-size=\"md\"\u003eNot compatible with 2016+ Yamaha 4-stroke models ending in “B”\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr data-end=\"2061\" data-start=\"2016\"\u003e\n\u003ctd data-col-size=\"sm\" data-end=\"2031\" data-start=\"2016\"\u003e\u003cstrong data-end=\"2030\" data-start=\"2018\"\u003eWarranty\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd data-end=\"2061\" data-start=\"2031\" data-col-size=\"md\"\u003e3-Year Fault-Free Warranty\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr data-end=\"2097\" data-start=\"2062\"\u003e\n\u003ctd data-col-size=\"sm\" data-end=\"2074\" data-start=\"2062\"\u003e\u003cstrong data-end=\"2073\" data-start=\"2064\"\u003eBrand\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd data-end=\"2097\" data-start=\"2074\" data-col-size=\"md\"\u003eSEI Marine Products\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n \u003c\/div\u003e\n\u003c\/div\u003e\n\u003chr data-end=\"2102\" data-start=\"2099\"\u003e\n\u003ch3 data-end=\"2156\" data-start=\"2104\"\u003e\u003cstrong data-end=\"2156\" data-start=\"2109\"\u003eWhy Choose This \u003ca href=\"https:\/\/yamahaoutboards.com\/\"\u003eYamaha\u003c\/a\u003e 75–100HP Lower Unit?\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp data-end=\"2481\" data-start=\"2157\"\u003eThis SEI replacement unit is a \u003cstrong data-end=\"2220\" data-start=\"2188\"\u003ecomplete, brand-new assembly\u003c\/strong\u003e — \u003cstrong data-end=\"2245\" data-start=\"2223\"\u003enot remanufactured\u003c\/strong\u003e — offering OEM-level reliability at a fraction of the cost. Each lower unit is \u003cstrong data-end=\"2352\" data-start=\"2325\"\u003efactory pressure-tested\u003c\/strong\u003e, \u003cstrong data-end=\"2374\" data-start=\"2354\"\u003eready to install\u003c\/strong\u003e, and includes \u003cstrong data-end=\"2421\" data-start=\"2389\"\u003epre-assembled internal gears\u003c\/strong\u003e and \u003cstrong data-end=\"2451\" data-start=\"2426\"\u003ewater pump components\u003c\/strong\u003e for effortless replacement.\u003c\/p\u003e\n\u003cp data-end=\"2653\" data-start=\"2483\"\u003eDesigned for Yamaha 75–100HP outboards\u003cbr data-end=\"2526\" data-start=\"2523\"\u003e100% brand new aftermarket replacement\u003cbr data-end=\"2618\" data-start=\"2615\"\u003eBacked by SEI’s 3-year warranty\u003c\/p\u003e\n\u003csection id=\"faq\"\u003e\u003chr data-end=\"2102\" data-start=\"2099\"\u003e\n\u003ch2\u003eFrequently Asked Questions – Yamaha 75–100HP Replacement Lower Unit\u003c\/h2\u003e\n\u003cdiv class=\"faq-item\"\u003e\n\u003ch3\u003e1. What Yamaha outboard models are compatible with this 75–100HP replacement lower unit?\u003c\/h3\u003e\nThis lower unit is designed for Yamaha 75HP to 100HP outboards manufactured between 1984 and 2017, including 2-stroke and 4-stroke engines. Compatible models include F75, F80, F90, F100, 90TLR, and E75. It fits standard rotation outboards and supports both 20″ and 25″ shaft lengths. Please note that it is not compatible with 2016+ 4-stroke Yamaha models ending in “B”.\u003c\/div\u003e\n\u003cdiv class=\"faq-item\"\u003e\n\u003ch3\u003e2. How do I choose the correct gear ratio and shaft length for my Yamaha 75–100HP lower unit?\u003c\/h3\u003e\nThe correct gear ratio depends on your existing Yamaha outboard's model and propeller setup. Most 75–90HP models use a 2.0:1 ratio, while select 100HP units use a 2.3:1 ratio. Shaft length should match your current unit — 20″ for standard (long shaft) and 25″ for extra-long shaft configurations. Refer to your engine’s model plate or Yamaha service manual for precise specifications before purchase.\u003c\/div\u003e\n\u003cdiv class=\"faq-item\"\u003e\n\u003ch3\u003e3. Is this SEI Marine Products lower unit an OEM or aftermarket assembly?\u003c\/h3\u003e\nThis is a brand-new aftermarket replacement lower unit manufactured by SEI Marine Products. It offers OEM-level performance and reliability but at a much lower cost. Each unit is 100% new (not rebuilt or remanufactured), factory pressure-tested, and pre-assembled with quality internal gears and water pump components, making installation direct and hassle-free.\u003c\/div\u003e\n\u003cdiv class=\"faq-item\"\u003e\n\u003ch3\u003e4. Does the Yamaha 75–100HP lower unit come pre-filled with oil or require setup before installation?\u003c\/h3\u003e\nThe unit ships dry and should be filled with high-quality marine gear lube before installation. Always add the manufacturer-recommended gear oil and replace the drain\/vent plugs with new seals. It comes ready to install with the water pump and gears pre-assembled, so setup is minimal aside from lubrication and alignment checks.\u003c\/div\u003e\n\u003cdiv class=\"faq-item\"\u003e\n\u003ch3\u003e5. What type of warranty coverage does this Yamaha replacement lower unit include?\u003c\/h3\u003e\nSEI Marine Products provides a 3-Year Fault-Free Warranty on all new Yamaha 75–100HP replacement lower units. This warranty covers any manufacturing or material defects and even includes replacement in the event of mechanical failure under normal recreational use. It’s one of the strongest aftermarket warranties available for Yamaha outboard lower units.\u003chr data-end=\"2102\" data-start=\"2099\"\u003e\n\u003c\/div\u003e\n\u003c\/section\u003e\n\u003ch4 data-end=\"2653\" data-start=\"2483\"\u003eLooking for other models or gear ratios?\u003c\/h4\u003e\n\u003cp data-end=\"2653\" data-start=\"2483\"\u003e\u003cbr data-end=\"487\" data-start=\"484\"\u003e\u003cstrong data-end=\"587\" data-start=\"490\"\u003e\u003ca href=\"\/pages\/yamaha-outboard-lower-unit\"\u003eBrowse all Yamaha Lower Units here\u003c\/a\u003e\u003ca data-end=\"585\" data-start=\"492\" rel=\"noopener\" href=\"https:\/\/allboatsupplies.com\/outboard-lower-unit\/yamaha\/\" class=\"decorated-link\"\u003e\u003c\/a\u003e\u003c\/strong\u003e — find compatible options for 40HP, 60HP, 115HP, 150HP, and more Yamaha outboards.\u003c\/p\u003e\n\u003cp\u003e \u003c\/p\u003e","brand":"All Marine Suppliers","offers":[{"title":"2.0:1 \/ 20\" \/ 2 Stroke","offer_id":47822941323523,"sku":"SE90-404-A20","price":1199.0,"currency_code":"USD","in_stock":true},{"title":"2.3:1 \/ 20\" \/ 4 Stroke","offer_id":47822941356291,"sku":"SE90-404-B20F","price":1199.0,"currency_code":"USD","in_stock":true},{"title":"2.3:1 \/ 25\" \/ 4 Stroke","offer_id":47822941389059,"sku":"SE90-404-B25F","price":1199.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0808\/2613\/8883\/files\/94c2e3b4-1.png?v=1772820575","url":"https:\/\/allmarinesuppliers.com\/products\/new-aftermarket-yamaha-75-100hp-outboard-lower-unit-90-404-2-4-stroke","provider":"All Marine Suppliers","version":"1.0","type":"link"}