{"product_id":"water-pump-base-46-44292a3-for-mercruiser-alpha-one-gen-1-mr-sterndrive-18-3420","title":"Water Pump Base 46-44292A3 for MerCruiser Alpha One Gen 1 MR Sterndrive 18-3420","description":"\u003ch2\u003eProduct Overview\u003c\/h2\u003e\n\u003cp\u003eWater pump base, a direct replacement part for MerCruiser MR and Alpha One Generation I sterndrives built from 1972 to 1990. It replaces MerCruiser 46-44292A3, 46-44292Q03 and 46-44292T1, and crosses to GLM 12320, Mallory 9-43308 and Sierra 18-3420. The base comes in a 150 mm x 100 mm x 40 mm box and weighs 155 g with packaging.\u003c\/p\u003e\n\n\u003cp\u003eThe base is the lower half of the water pump housing. The impeller runs against it, so its bore and sealing face set how much water the pump moves. Once the bore is scored or the seal face is worn, a new impeller alone will not restore flow.\u003c\/p\u003e\n\n\u003cp\u003eThe casting is the original pattern, with the same bolt spacing and the same water passage as the Mercury part. It takes the standard impeller and wear plate for these drives, so it can be fitted to a pump you already have apart rather than ordering a whole housing.\u003c\/p\u003e\n\n\u003cp\u003eFitment runs across two groups on our eBay listings: the MerCruiser MR sterndrive from 1972 to 1982 and the Alpha One Generation I from 1983 to 1990, plus the Mercury, Mariner and Force L4, L6 and V6 two stroke outboards from 65-225 HP. Check the drive model and the year before ordering.\u003c\/p\u003e\n\n\u003ch2\u003eSpecifications\u003c\/h2\u003e\n\u003ctable style=\"width:100%;border-collapse:collapse\"\u003e\n\u003cthead\u003e\u003ctr\u003e\n\u003cth style=\"text-align:left;border-bottom:1px solid #ddd;padding:6px\"\u003eSpecification\u003c\/th\u003e\n\u003cth style=\"text-align:left;border-bottom:1px solid #ddd;padding:6px\"\u003eDetail\u003c\/th\u003e\n\u003c\/tr\u003e\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding:6px\"\u003eCondition\u003c\/td\u003e\n\u003ctd style=\"padding:6px\"\u003eNew \/ New with tags\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding:6px\"\u003eType\u003c\/td\u003e\n\u003ctd style=\"padding:6px\"\u003eWater pump base, lower housing\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding:6px\"\u003eMerCruiser Part Numbers\u003c\/td\u003e\n\u003ctd style=\"padding:6px\"\u003e46-44292A3, 46-44292Q03, 46-44292T1\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding:6px\"\u003eGLM Cross Reference\u003c\/td\u003e\n\u003ctd style=\"padding:6px\"\u003e12320\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding:6px\"\u003eMallory Cross Reference\u003c\/td\u003e\n\u003ctd style=\"padding:6px\"\u003e9-43308\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding:6px\"\u003eSierra Cross Reference\u003c\/td\u003e\n\u003ctd style=\"padding:6px\"\u003e18-3420\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding:6px\"\u003eFits\u003c\/td\u003e\n\u003ctd style=\"padding:6px\"\u003eMerCruiser MR and Alpha One Gen I sterndrives\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding:6px\"\u003eFits Years\u003c\/td\u003e\n\u003ctd style=\"padding:6px\"\u003e1972 to 1990\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding:6px\"\u003eAlso Listed For\u003c\/td\u003e\n\u003ctd style=\"padding:6px\"\u003eMercury, Mariner and Force L4, L6 and V6 two strokes, 65 HP to 225 HP\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding:6px\"\u003eMaterial\u003c\/td\u003e\n\u003ctd style=\"padding:6px\"\u003eMarine grade cast alloy\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding:6px\"\u003ePackage Contents\u003c\/td\u003e\n\u003ctd style=\"padding:6px\"\u003e1 x water pump base\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding:6px\"\u003eNet Weight\u003c\/td\u003e\n\u003ctd style=\"padding:6px\"\u003e155 g including packaging\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding:6px\"\u003ePack Size\u003c\/td\u003e\n\u003ctd style=\"padding:6px\"\u003e150 mm x 100 mm x 40 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding:6px\"\u003ePack Size In Inches\u003c\/td\u003e\n\u003ctd style=\"padding:6px\"\u003e5.91 in x 3.94 in x 1.57 in\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding:6px\"\u003eWarranty\u003c\/td\u003e\n\u003ctd style=\"padding:6px\"\u003e3 year\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\n\u003ch2\u003eOEM Cross Reference\u003c\/h2\u003e\u003ctable style=\"width:100%;border-collapse:collapse\"\u003e\n\u003cthead\u003e\u003ctr\u003e\n\u003cth style=\"text-align:left;border-bottom:1px solid #ddd;padding:6px\"\u003eBrand\u003c\/th\u003e\n\u003cth style=\"text-align:left;border-bottom:1px solid #ddd;padding:6px\"\u003ePart Numbers\u003c\/th\u003e\n\u003c\/tr\u003e\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding:6px\"\u003eMerCruiser\u003c\/td\u003e\n\u003ctd style=\"padding:6px\"\u003e46-44292A3, 46-44292Q03, 46-44292T1\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding:6px\"\u003eMercury Marine\u003c\/td\u003e\n\u003ctd style=\"padding:6px\"\u003e46-44292A3, 46-44292Q03, 46-44292T1\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding:6px\"\u003eGLM\u003c\/td\u003e\n\u003ctd style=\"padding:6px\"\u003e12320\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding:6px\"\u003eMallory\u003c\/td\u003e\n\u003ctd style=\"padding:6px\"\u003e9-43308\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding:6px\"\u003eSierra\u003c\/td\u003e\n\u003ctd style=\"padding:6px\"\u003e18-3420\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\n\u003ch2\u003eCompatible Engines\u003c\/h2\u003e\u003ctable style=\"width:100%;border-collapse:collapse\"\u003e\n\u003cthead\u003e\u003ctr\u003e\n\u003cth style=\"text-align:left;border-bottom:1px solid #ddd;padding:6px\"\u003eBrand\u003c\/th\u003e\n\u003cth style=\"text-align:left;border-bottom:1px solid #ddd;padding:6px\"\u003eModel\u003c\/th\u003e\n\u003cth style=\"text-align:left;border-bottom:1px solid #ddd;padding:6px\"\u003eYears\u003c\/th\u003e\n\u003cth style=\"text-align:left;border-bottom:1px solid #ddd;padding:6px\"\u003eNotes\u003c\/th\u003e\n\u003c\/tr\u003e\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding:6px\"\u003eMerCruiser\u003c\/td\u003e\n\u003ctd style=\"padding:6px\"\u003eMR sterndrive\u003c\/td\u003e\n\u003ctd style=\"padding:6px\"\u003e1972 to 1982\u003c\/td\u003e\n\u003ctd style=\"padding:6px\"\u003eGeneration I pump\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding:6px\"\u003eMerCruiser\u003c\/td\u003e\n\u003ctd style=\"padding:6px\"\u003eAlpha One Generation I sterndrive\u003c\/td\u003e\n\u003ctd style=\"padding:6px\"\u003e1983 to 1990\u003c\/td\u003e\n\u003ctd style=\"padding:6px\"\u003eGeneration I pump\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding:6px\"\u003eMercury\u003c\/td\u003e\n\u003ctd style=\"padding:6px\"\u003eL4, L6 and V6 two stroke\u003c\/td\u003e\n\u003ctd style=\"padding:6px\"\u003e65 HP to 225 HP\u003c\/td\u003e\n\u003ctd style=\"padding:6px\"\u003eAs listed on our outboard fitment\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding:6px\"\u003eMariner\u003c\/td\u003e\n\u003ctd style=\"padding:6px\"\u003eL4, L6 and V6 two stroke\u003c\/td\u003e\n\u003ctd style=\"padding:6px\"\u003e65 HP to 225 HP\u003c\/td\u003e\n\u003ctd style=\"padding:6px\"\u003eAs listed on our outboard fitment\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding:6px\"\u003eForce\u003c\/td\u003e\n\u003ctd style=\"padding:6px\"\u003eL4, L6 and V6 two stroke\u003c\/td\u003e\n\u003ctd style=\"padding:6px\"\u003e65 HP to 225 HP\u003c\/td\u003e\n\u003ctd style=\"padding:6px\"\u003eAs listed on our outboard fitment\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\n\u003ch2\u003eWhat's Included\u003c\/h2\u003e\u003ctable style=\"width:100%;border-collapse:collapse\"\u003e\n\u003cthead\u003e\u003ctr\u003e\n\u003cth style=\"text-align:left;border-bottom:1px solid #ddd;padding:6px\"\u003eComponent\u003c\/th\u003e\n\u003cth style=\"text-align:left;border-bottom:1px solid #ddd;padding:6px\"\u003eDetail\u003c\/th\u003e\n\u003cth style=\"text-align:left;border-bottom:1px solid #ddd;padding:6px\"\u003eQty\u003c\/th\u003e\n\u003c\/tr\u003e\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding:6px\"\u003eWater pump base\u003c\/td\u003e\n\u003ctd style=\"padding:6px\"\u003e46-44292A3, complete lower housing\u003c\/td\u003e\n\u003ctd style=\"padding:6px\"\u003e1\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding:6px\"\u003eImpeller\u003c\/td\u003e\n\u003ctd style=\"padding:6px\"\u003eNot included, sold separately\u003c\/td\u003e\n\u003ctd style=\"padding:6px\"\u003e0\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding:6px\"\u003eWear plate\u003c\/td\u003e\n\u003ctd style=\"padding:6px\"\u003eNot included, sold separately\u003c\/td\u003e\n\u003ctd style=\"padding:6px\"\u003e0\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding:6px\"\u003eGaskets\u003c\/td\u003e\n\u003ctd style=\"padding:6px\"\u003eNot included, sold separately\u003c\/td\u003e\n\u003ctd style=\"padding:6px\"\u003e0\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\n\u003ch2\u003eSigns The Base Needs Replacing\u003c\/h2\u003e\u003ctable style=\"width:100%;border-collapse:collapse\"\u003e\n\u003cthead\u003e\u003ctr\u003e\n\u003cth style=\"text-align:left;border-bottom:1px solid #ddd;padding:6px\"\u003eWhat You See\u003c\/th\u003e\n\u003cth style=\"text-align:left;border-bottom:1px solid #ddd;padding:6px\"\u003eWhat It Means\u003c\/th\u003e\n\u003cth style=\"text-align:left;border-bottom:1px solid #ddd;padding:6px\"\u003eWhat To Do\u003c\/th\u003e\n\u003c\/tr\u003e\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding:6px\"\u003eNew impeller but still overheating\u003c\/td\u003e\n\u003ctd style=\"padding:6px\"\u003eBase bore worn, blades cannot seal\u003c\/td\u003e\n\u003ctd style=\"padding:6px\"\u003eFit the new base\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding:6px\"\u003eDeep grooves in the bore\u003c\/td\u003e\n\u003ctd style=\"padding:6px\"\u003eSand or grit run through the pump\u003c\/td\u003e\n\u003ctd style=\"padding:6px\"\u003eFit the new base\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding:6px\"\u003eWhite corrosion on the sealing face\u003c\/td\u003e\n\u003ctd style=\"padding:6px\"\u003eSalt water attack on the casting\u003c\/td\u003e\n\u003ctd style=\"padding:6px\"\u003eFit the new base\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding:6px\"\u003eWater in the gear oil\u003c\/td\u003e\n\u003ctd style=\"padding:6px\"\u003eSeal face gone, water past the pump\u003c\/td\u003e\n\u003ctd style=\"padding:6px\"\u003eFit the new base and reseal\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding:6px\"\u003eTell tale weak at idle\u003c\/td\u003e\n\u003ctd style=\"padding:6px\"\u003ePump clearances out of spec\u003c\/td\u003e\n\u003ctd style=\"padding:6px\"\u003eFit the new base and impeller\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding:6px\"\u003eBase cracked around a bolt hole\u003c\/td\u003e\n\u003ctd style=\"padding:6px\"\u003eOver tightened or frozen bolt\u003c\/td\u003e\n\u003ctd style=\"padding:6px\"\u003eFit the new base\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\n\u003ch2\u003eFitting Notes\u003c\/h2\u003e\u003ctable style=\"width:100%;border-collapse:collapse\"\u003e\n\u003cthead\u003e\u003ctr\u003e\n\u003cth style=\"text-align:left;border-bottom:1px solid #ddd;padding:6px\"\u003eStep\u003c\/th\u003e\n\u003cth style=\"text-align:left;border-bottom:1px solid #ddd;padding:6px\"\u003eAction\u003c\/th\u003e\n\u003c\/tr\u003e\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding:6px\"\u003e1\u003c\/td\u003e\n\u003ctd style=\"padding:6px\"\u003eRead the drive model and year and check the table above\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding:6px\"\u003e2\u003c\/td\u003e\n\u003ctd style=\"padding:6px\"\u003ePut the drive in gear, remove the propeller and split the lower unit\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding:6px\"\u003e3\u003c\/td\u003e\n\u003ctd style=\"padding:6px\"\u003eTake the pump housing and impeller off and note the blade direction\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding:6px\"\u003e4\u003c\/td\u003e\n\u003ctd style=\"padding:6px\"\u003eRemove the base and clean the mating face on the gear housing\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding:6px\"\u003e5\u003c\/td\u003e\n\u003ctd style=\"padding:6px\"\u003eCheck the new base sits flat with no gap under it\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding:6px\"\u003e6\u003c\/td\u003e\n\u003ctd style=\"padding:6px\"\u003eFit the new base, then the wear plate and gasket, then the impeller\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding:6px\"\u003e7\u003c\/td\u003e\n\u003ctd style=\"padding:6px\"\u003eRefit the housing and tighten the bolts evenly in a cross pattern\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding:6px\"\u003e8\u003c\/td\u003e\n\u003ctd style=\"padding:6px\"\u003eTurn the driveshaft by hand to check the impeller turns freely\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding:6px\"\u003e9\u003c\/td\u003e\n\u003ctd style=\"padding:6px\"\u003eRun the engine on muffs and confirm a strong tell tale before you launch\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\n\u003ch2\u003eCondition \u0026amp; Warranty\u003c\/h2\u003e\n\u003ctable style=\"width:100%;border-collapse:collapse\"\u003e\n\u003cthead\u003e\u003ctr\u003e\n\u003cth style=\"text-align:left;border-bottom:1px solid #ddd;padding:6px\"\u003eItem\u003c\/th\u003e\n\u003cth style=\"text-align:left;border-bottom:1px solid #ddd;padding:6px\"\u003eDetail\u003c\/th\u003e\n\u003c\/tr\u003e\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding:6px\"\u003eCondition\u003c\/td\u003e\n\u003ctd style=\"padding:6px\"\u003eNew \/ New with tags\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding:6px\"\u003eWarranty\u003c\/td\u003e\n\u003ctd style=\"padding:6px\"\u003e3 year\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding:6px\"\u003ePackaging\u003c\/td\u003e\n\u003ctd style=\"padding:6px\"\u003eSealed retail packaging\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\n\u003ch2\u003eBefore You Buy\u003c\/h2\u003e\n\u003cul style=\"list-style:none\"\u003e\n\u003cli\u003eFits MerCruiser MR sterndrives from 1972 to 1982\u003c\/li\u003e\n\u003cli\u003eFits MerCruiser Alpha One Generation I sterndrives from 1983 to 1990\u003c\/li\u003e\n\u003cli\u003eAlso listed for Mercury, Mariner and Force L4, L6 and V6 two strokes from 65 HP to 225 HP\u003c\/li\u003e\n\u003cli\u003eReplaces MerCruiser 46-44292A3, 46-44292Q03 and 46-44292T1\u003c\/li\u003e\n\u003cli\u003eCrosses to GLM 12320, Mallory 9-43308 and Sierra 18-3420\u003c\/li\u003e\n\u003cli\u003eMarine grade cast alloy, original pattern bore and bolt spacing\u003c\/li\u003e\n\u003cli\u003e155 g with packaging, box 150 mm x 100 mm x 40 mm\u003c\/li\u003e\n\u003cli\u003e30-Day Easy Returns\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"XRmarine","offers":[{"title":"Default Title","offer_id":68119721345067,"sku":"2046","price":17.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0689\/0415\/7227\/files\/10_1229fbf6-0bfb-4c6c-8248-4ea1a9b8ef89.jpg?v=1793763326","url":"https:\/\/xrmarineparts.com\/de\/products\/water-pump-base-46-44292a3-for-mercruiser-alpha-one-gen-1-mr-sterndrive-18-3420","provider":"XRmarine","version":"1.0","type":"link"}