{"product_id":"water-pump-impeller-kit-fits-mercury-mariner-30-70-hp-2-stroke-outboards-replaces-77177a3-46-77177a3","title":"Water Pump Impeller Kit – Fits Mercury\/Mariner 30-70 HP 2-Stroke Outboards (Replaces 77177A3, 46-77177A3)","description":"\u003csection\u003e\n\n\u003ch2\u003eProduct Details\u003c\/h2\u003e\n\u003cp\u003eThis \u003cstrong\u003eWater Pump Impeller Kit\u003c\/strong\u003e provides a complete solution for servicing the lower unit of Mercury\/Mariner 2-stroke outboard motors from 30–70 HP (1977–1997). It is designed to restore cooling system performance and prevent engine overheating on models including 30 JET, 35 HP, 40 HP, 45 HP, 50 HP, 60 HP, 65 HP, and 70 HP.\u003c\/p\u003e\n\u003cp\u003eIt serves as a direct interchange for several part numbers, including Mercury 46-77177A3\/77177A3, Sierra 18-3324, Mallory 9-48312, and GLM 12100, ensuring broad compatibility for repairs and maintenance.\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eInstallation Location:\u003c\/strong\u003e Mounts in the lower unit\/gearcase as a direct-fit replacement.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eHousing Material:\u003c\/strong\u003e Constructed from durable Nylon PA66 plastic for longevity.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eComplete Kit:\u003c\/strong\u003e Includes the impeller, upper housing, base, face plate, and all required gaskets and seals for a comprehensive overhaul.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003c!-- 🔧 Table Styles (include only once per page) --\u003e\n\u003cstyle\u003e\n  \/* Outer container allows horizontal scrolling (with iOS momentum) *\/\n  .ss-table-wrap { overflow-x:auto; -webkit-overflow-scrolling:touch; }\n\n  \/* Base table styles *\/\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\n  \/* Key: prevent wrapping, word breaks, and vertical text in headers *\/\n  table.ss-table th {\n    white-space:nowrap;       \/* Do not wrap *\/\n    word-break:normal;        \/* Don’t break words *\/\n    letter-spacing:normal;    \/* Prevent theme styles from stretching letters *\/\n    font-weight:600;\n    background:#f8fafc;\n  }\n\n  \/* Small screen optimization *\/\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\u003ePart Number Matrix\u003c\/h2\u003e\n\u003cp\u003eUse this matrix to confirm equivalent references across OEM and aftermarket providers.\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      \u003c\/tr\u003e\n    \u003c\/thead\u003e\n    \u003ctbody\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eMercury\u003c\/td\u003e\n        \u003ctd\u003e46-77177A3\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eMercury\u003c\/td\u003e\n        \u003ctd\u003e77177A3\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eSierra\u003c\/td\u003e\n        \u003ctd\u003e18-3324\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eMallory\u003c\/td\u003e\n        \u003ctd\u003e9-48312\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eGLM\u003c\/td\u003e\n        \u003ctd\u003e12100\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. Serial numbers are critical for ensuring correct fitment.\u003c\/p\u003e\n\u003cdiv class=\"ss-table-wrap\"\u003e\n  \u003ctable class=\"ss-table\" aria-label=\"Engine \u0026amp; Model Compatibility\"\u003e\n    \u003cthead\u003e\n      \u003ctr\u003e\n        \u003cth\u003eBrand\u003c\/th\u003e\n        \u003cth\u003eModel\u003c\/th\u003e\n        \u003cth\u003eRated HP\u003c\/th\u003e\n        \u003cth\u003eStroke\u003c\/th\u003e\n        \u003cth\u003eYears\u003c\/th\u003e\n        \u003cth\u003eOEM Part No.\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\u003eMercury\u003c\/td\u003e\n        \u003ctd\u003e30 JET\u003c\/td\u003e\n        \u003ctd\u003e30\u003c\/td\u003e\n        \u003ctd\u003e2-Stroke\u003c\/td\u003e\n        \u003ctd\u003e1989–1997\u003c\/td\u003e\n        \u003ctd\u003e46-77177A3\u003c\/td\u003e\n        \u003ctd\u003eSerial # 0C159200-0G589999\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eMercury\u003c\/td\u003e\n        \u003ctd\u003e35\u003c\/td\u003e\n        \u003ctd\u003e35\u003c\/td\u003e\n        \u003ctd\u003e2-Stroke\u003c\/td\u003e\n        \u003ctd\u003e1984–1989\u003c\/td\u003e\n        \u003ctd\u003e46-77177A3\u003c\/td\u003e\n        \u003ctd\u003eSerial # 6445653 \u0026amp; Up\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eMercury\u003c\/td\u003e\n        \u003ctd\u003e402\u003c\/td\u003e\n        \u003ctd\u003e40\u003c\/td\u003e\n        \u003ctd\u003e2-Stroke\u003c\/td\u003e\n        \u003ctd\u003e1978–1979\u003c\/td\u003e\n        \u003ctd\u003e46-77177A3\u003c\/td\u003e\n        \u003ctd\u003eSerial # 4860103-5556229\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eMercury\u003c\/td\u003e\n        \u003ctd\u003e40 (2 CYL)\u003c\/td\u003e\n        \u003ctd\u003e40\u003c\/td\u003e\n        \u003ctd\u003e2-Stroke\u003c\/td\u003e\n        \u003ctd\u003e1980–1983\u003c\/td\u003e\n        \u003ctd\u003e46-77177A3\u003c\/td\u003e\n        \u003ctd\u003eSerial # 5556230-6445653\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eMercury\u003c\/td\u003e\n        \u003ctd\u003e40 (4 CYL)\u003c\/td\u003e\n        \u003ctd\u003e40\u003c\/td\u003e\n        \u003ctd\u003e2-Stroke\u003c\/td\u003e\n        \u003ctd\u003e1989–1997\u003c\/td\u003e\n        \u003ctd\u003e46-77177A3\u003c\/td\u003e\n        \u003ctd\u003eSerial # 0C159200 \u0026amp; Up\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eMercury\u003c\/td\u003e\n        \u003ctd\u003e45 (4 CYL)\u003c\/td\u003e\n        \u003ctd\u003e45\u003c\/td\u003e\n        \u003ctd\u003e2-Stroke\u003c\/td\u003e\n        \u003ctd\u003e1986–1997\u003c\/td\u003e\n        \u003ctd\u003e46-77177A3\u003c\/td\u003e\n        \u003ctd\u003eSerial # 5531630 \u0026amp; Up\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eMercury\u003c\/td\u003e\n        \u003ctd\u003e50 (4 CYL)\u003c\/td\u003e\n        \u003ctd\u003e50\u003c\/td\u003e\n        \u003ctd\u003e2-Stroke\u003c\/td\u003e\n        \u003ctd\u003e1978–1985\u003c\/td\u003e\n        \u003ctd\u003e46-77177A3\u003c\/td\u003e\n        \u003ctd\u003eSerial # 496205-6 \u0026amp; Up\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eMercury\u003c\/td\u003e\n        \u003ctd\u003e50 (3 CYL)\u003c\/td\u003e\n        \u003ctd\u003e50\u003c\/td\u003e\n        \u003ctd\u003e2-Stroke\u003c\/td\u003e\n        \u003ctd\u003e1984–1990\u003c\/td\u003e\n        \u003ctd\u003e46-77177A3\u003c\/td\u003e\n        \u003ctd\u003eSerial # 6428681-0D000749\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eMercury\u003c\/td\u003e\n        \u003ctd\u003e60 (3 CYL)\u003c\/td\u003e\n        \u003ctd\u003e60\u003c\/td\u003e\n        \u003ctd\u003e2-Stroke\u003c\/td\u003e\n        \u003ctd\u003e1984–1990\u003c\/td\u003e\n        \u003ctd\u003e46-77177A3\u003c\/td\u003e\n        \u003ctd\u003eSerial # 6428681-0D000749\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eMercury\u003c\/td\u003e\n        \u003ctd\u003e65 (650) (3 CYL)\u003c\/td\u003e\n        \u003ctd\u003e65\u003c\/td\u003e\n        \u003ctd\u003e2-Stroke\u003c\/td\u003e\n        \u003ctd\u003e1976\u003c\/td\u003e\n        \u003ctd\u003e46-77177A3\u003c\/td\u003e\n        \u003ctd\u003eSerial # 4382057-4571651\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eMercury\u003c\/td\u003e\n        \u003ctd\u003e70 (3 CYL)\u003c\/td\u003e\n        \u003ctd\u003e70\u003c\/td\u003e\n        \u003ctd\u003e2-Stroke\u003c\/td\u003e\n        \u003ctd\u003e1979–1983\u003c\/td\u003e\n        \u003ctd\u003e46-77177A3\u003c\/td\u003e\n        \u003ctd\u003eSerial # 4977157-6428680\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\u003eWater Pump Impeller Kit with Housing\u003c\/dd\u003e\n  \u003cdt\u003eInstallation\u003c\/dt\u003e\n\u003cdd\u003eLower unit\/gearcase replacement\u003c\/dd\u003e\n  \u003cdt\u003eHousing Material\u003c\/dt\u003e\n\u003cdd\u003eNylon PA66 Plastic\u003c\/dd\u003e\n  \u003cdt\u003eHousing Color\u003c\/dt\u003e\n\u003cdd\u003eBlack\u003c\/dd\u003e\n  \u003cdt\u003eDimensions\u003c\/dt\u003e\n\u003cdd\u003e152.4 mm × 102.9 mm × 52.1 mm (6\" × 4.06\" × 2.05\")\u003c\/dd\u003e\n  \u003cdt\u003eWeight\u003c\/dt\u003e\n\u003cdd\u003e0.22 kg (0.5 lb)\u003c\/dd\u003e\n  \u003cdt\u003eWarranty\u003c\/dt\u003e\n\u003cdd\u003e30-day return\/replacement (Amazon standard)\u003c\/dd\u003e\n  \u003cdt\u003eOther Technical Attributes\u003c\/dt\u003e\n\u003cdd\u003eComplete kit including impeller, housing, and all required gaskets\u003c\/dd\u003e\n\u003c\/dl\u003e\n\n\u003ch2\u003eWhat’s in the Box\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003e1 x \u003cspan style=\"color:#d0021b;\"\u003eWater Pump Impeller (47-89983T)\u003c\/span\u003e\n\u003c\/li\u003e\n\u003cli\u003e1 x \u003cspan style=\"color:#d0021b;\"\u003eUpper Pump Housing (77822A1)\u003c\/span\u003e\n\u003c\/li\u003e\n\u003cli\u003e1 x Water Pump Base (46-77177A1)\u003c\/li\u003e\n\u003cli\u003e1 x Face Plate (32768\/54705)\u003c\/li\u003e\n\u003cli\u003e1 x Impeller Key (8M0032837)\u003c\/li\u003e\n\u003cli\u003e1 x Drain Gasket (12-20260)\u003c\/li\u003e\n\u003cli\u003e1 x Lower Water Pump Base to Face Plate Gasket (27-19553)\u003c\/li\u003e\n\u003cli\u003e1 x Upper Face Plate to Body Gasket (27-32770\/27-19551)\u003c\/li\u003e\n\u003cli\u003e1 x Water Pump Base Gasket (27-32771)\u003c\/li\u003e\n\u003cli\u003e1 x Water Pump Base Gasket (27-77417\/27-19552)\u003c\/li\u003e\n\u003cli\u003e1 x Drain Plug (12-49221-1)\u003c\/li\u003e\n\u003cli\u003e1 x O-Ring (25-26722)\u003c\/li\u003e\n\u003cli\u003e1 x Rubber Washer (25-20273)\u003c\/li\u003e\n\u003cli\u003eVarious seals and additional O-rings\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2\u003eInstallation Notes\u003c\/h2\u003e\n\u003col\u003e\n\u003cli\u003eDisconnect the engine's battery and shift the outboard into the neutral position.\u003c\/li\u003e\n\u003cli\u003eLocate and remove the lower unit (gearcase) mounting bolts, allowing the unit to drop down.\u003c\/li\u003e\n\u003cli\u003eCarefully unbolt and detach the old water pump housing assembly from the lower unit.\u003c\/li\u003e\n\u003cli\u003eRemove the old impeller, face plate, gaskets, and impeller key from the driveshaft.\u003c\/li\u003e\n\u003cli\u003eThoroughly clean all mating surfaces, removing any old gasket material or corrosion.\u003c\/li\u003e\n\u003cli\u003eInstall the new lower gasket, face plate, and impeller key onto the driveshaft.\u003c\/li\u003e\n\u003cli\u003eSlide the new impeller onto the driveshaft, turning the shaft clockwise to bed the vanes correctly.\u003c\/li\u003e\n\u003cli\u003eApply a thin layer of marine grease to the inside of the new housing and install it with new gaskets.\u003c\/li\u003e\n\u003cli\u003eSecurely tighten the housing bolts to the manufacturer's recommended torque.\u003c\/li\u003e\n\u003cli\u003eRe-install the lower unit, ensuring the driveshaft, shift shaft, and water tube are properly aligned.\u003c\/li\u003e\n\u003cli\u003eTighten the lower unit bolts, reconnect the battery, and test the engine in water to verify a strong telltale stream.\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 motor?\u003c\/summary\u003e\n  \u003cp\u003eCheck your motor's model, HP, and serial number against the \"Engine \u0026amp; Model Compatibility\" table. This kit fits specific Mercury and Mariner 30-70 HP 2-stroke outboards from 1977–1997. The serial number is critical for an exact match.\u003c\/p\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n  \u003csummary\u003eWhat are the signs of a failing water pump impeller?\u003c\/summary\u003e\n  \u003cp\u003eCommon signs include a weak or non-existent water stream from the \"telltale\" outlet, engine overheating alarms, steam from the exhaust, and reduced engine performance, especially at low speeds.\u003c\/p\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n  \u003csummary\u003eHow often should the water pump impeller be replaced?\u003c\/summary\u003e\n  \u003cp\u003eFor preventative maintenance, it is recommended to inspect the impeller annually and replace it every 1-2 years or every 100-200 hours of operation. Replacement frequency should be increased in saltwater or high-sediment environments.\u003c\/p\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n  \u003csummary\u003eIs the housing included in this kit?\u003c\/summary\u003e\n  \u003cp\u003eYes, this is a complete kit that includes the upper pump housing, water pump base, impeller, face plate, gaskets, and all necessary seals and O-rings for a full replacement.\u003c\/p\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n  \u003csummary\u003eMy serial number isn't listed but the model and year match. Will it fit?\u003c\/summary\u003e\n  \u003cp\u003eWe strongly advise against purchasing if your serial number does not fall within the specified ranges. Manufacturers often make mid-year design changes, and the serial number is the only way to guarantee correct fitment.\u003c\/p\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n  \u003csummary\u003eWhat is the difference between an OEM part and this aftermarket kit?\u003c\/summary\u003e\n  \u003cp\u003eThis listing is an aftermarket replacement (not OEM). It is built to OEM-level specifications with comparable materials. All our parts are manufactured in an ISO 9002 certified facility and are batch-inspected for quality and consistency.\u003c\/p\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n  \u003csummary\u003eHow fast is shipping and what does it cost?\u003c\/summary\u003e\n  \u003cp\u003eWe ship worldwide quickly—typical transit time is 5–15 days. Standard shipping is free to most regions, with expedited options available at checkout where applicable.\u003c\/p\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n  \u003csummary\u003eWhat is the warranty and return policy?\u003c\/summary\u003e\n  \u003cp\u003eThis kit is covered by a 1-year warranty against manufacturing defects under normal use. If you encounter any issues, contact our support team with your order details. Returns are accepted within our standard window for items that are unused and in their original condition. Please see our policy page or reach out for instructions.\u003c\/p\u003e\n\u003c\/details\u003e\n\n\u003ch2\u003eSafety \u0026amp; Important Info\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003eVerify images and 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 part, not an original equipment manufacturer (OEM) component.\u003c\/li\u003e\n\u003cli\u003eProfessional installation is highly recommended for safety, performance, and to prevent damage to your engine.\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 engineered to OEM-level tolerances and rigorously tested for real-world conditions.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFast Global Fulfillment\u003c\/strong\u003e — Enjoy free standard delivery to most regions in 5–15 days, with expedited options available.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eManufacturer-Direct Value\u003c\/strong\u003e — We deliver fair pricing on reliable components by eliminating middlemen, without compromising on materials or quality control.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003c\/section\u003e","brand":"SeaSierra","offers":[{"title":"Default Title","offer_id":50723964780859,"sku":"rVZK5dRtnX3","price":29.89,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0826\/8673\/8747\/files\/rVZK5dRtnX3.png?v=1763038560","url":"https:\/\/seasierra.com\/products\/water-pump-impeller-kit-fits-mercury-mariner-30-70-hp-2-stroke-outboards-replaces-77177a3-46-77177a3","provider":"SeaSierra","version":"1.0","type":"link"}