{"product_id":"mercury-base-assy-w-p-46-42579a3","title":"Mercury – Water Pump Base Assembly | Cooling System | 46-42579A3","description":"\u003cp data-start=\"0\" data-end=\"66\"\u003eMercury – Water Pump Base Assembly | Cooling System | 46-42579A3\u003c\/p\u003e\n\u003chr data-start=\"68\" data-end=\"71\"\u003e\n\u003ch3 data-start=\"73\" data-end=\"87\"\u003eOverview\u003c\/h3\u003e\n\u003cp data-start=\"88\" data-end=\"677\"\u003eIf you’ve spent any time working on the mid-range Mercury or Mariner 2-strokes—especially the 105–220HP EFI, DFI, or 2.5L jet motors—you already know the water pump doesn’t forgive a worn base. Once that base plate gets chewed up or warped, the impeller can’t build good pressure, and you start seeing weak water flow or temps creeping higher than you’re comfortable with. This OEM base assembly is the proper replacement and gives the pump a clean surface to work against again. It’s one of those parts that looks simple, but if it’s not right, nothing else in the cooling system behaves.\u003c\/p\u003e\n\u003chr data-start=\"679\" data-end=\"682\"\u003e\n\u003ch3 data-start=\"684\" data-end=\"702\"\u003eKey Features\u003c\/h3\u003e\n\u003cp data-start=\"703\" data-end=\"1189\"\u003e • \u003cstrong data-start=\"706\" data-end=\"750\"\u003eBuilt for 105–220HP 2-Stroke EFI\/DFI\/Jet\u003c\/strong\u003e – Correct base for select Mercury and Mariner 2.5L engines.\u003cbr data-start=\"810\" data-end=\"813\"\u003e • \u003cstrong data-start=\"816\" data-end=\"850\"\u003eRestores Water Pump Efficiency\u003c\/strong\u003e – Helps bring back strong telltale flow and steady temps.\u003cbr data-start=\"908\" data-end=\"911\"\u003e • \u003cstrong data-start=\"914\" data-end=\"943\"\u003eTough Marine Construction\u003c\/strong\u003e – Handles heat, grit, vibration, and constant water pressure.\u003cbr data-start=\"1005\" data-end=\"1008\"\u003e • \u003cstrong data-start=\"1011\" data-end=\"1027\"\u003eEasy Install\u003c\/strong\u003e – Swaps in when you’ve already dropped the lower unit for pump service.\u003cbr data-start=\"1099\" data-end=\"1102\"\u003e • \u003cstrong data-start=\"1105\" data-end=\"1123\"\u003eOEM Tolerances\u003c\/strong\u003e – Ensures the impeller sits properly and seals the way it should.\u003c\/p\u003e\n\u003chr data-start=\"1191\" data-end=\"1194\"\u003e\n\u003ch3 data-start=\"1196\" data-end=\"1229\"\u003eEngine \u0026amp; Boat Compatibility\u003c\/h3\u003e\n\u003cp data-start=\"1230\" data-end=\"1360\"\u003e • Mercury 105–220HP EFI\u003cbr data-start=\"1254\" data-end=\"1257\"\u003e • Mercury 105–220HP DFI\u003cbr data-start=\"1281\" data-end=\"1284\"\u003e • Mercury\/Mariner 2.5L Jet outboards\u003cbr data-start=\"1321\" data-end=\"1324\"\u003e • Select 2-stroke cooling systems\u003c\/p\u003e\n\u003chr data-start=\"1362\" data-end=\"1365\"\u003e\n\u003ch3 data-start=\"1367\" data-end=\"1405\"\u003ePerformance \u0026amp; Practical Benefits\u003c\/h3\u003e\n\u003cp data-start=\"1406\" data-end=\"1886\"\u003eOnce you put a fresh base in, you’ll usually notice the cooling system straighten up fast. The telltale steadies, temps stay where they belong, and the motor stops flirting with overheating at idle or during long no-wake stretches. Jet motors especially chew through bases over time thanks to sand and shallow water, so replacing this piece can make the whole pump feel brand-new again. And it helps your new impeller last longer instead of grinding itself against a worn surface.\u003c\/p\u003e\n\u003chr data-start=\"1888\" data-end=\"1891\"\u003e\n\u003ch3 data-start=\"1893\" data-end=\"1910\"\u003eWhy Buy OEM\u003c\/h3\u003e\n\u003cp data-start=\"1911\" data-end=\"2151\"\u003eWith OEM, the fit is right and the material holds up. Aftermarket bases can warp, crack, or leak—sometimes right out of the box. Cooling issues on these engines get expensive fast, so running the correct Mercury part is just the smart play.\u003c\/p\u003e\n\u003chr data-start=\"2153\" data-end=\"2156\"\u003e\n\u003ch3 data-start=\"2158\" data-end=\"2167\"\u003eFAQ\u003c\/h3\u003e\n\u003cp data-start=\"2168\" data-end=\"2314\"\u003e\u003cstrong data-start=\"2168\" data-end=\"2217\"\u003eQ1: What tells me the base might be worn out?\u003c\/strong\u003e\u003cbr data-start=\"2217\" data-end=\"2220\"\u003e\u003cstrong data-start=\"2220\" data-end=\"2226\"\u003eA:\u003c\/strong\u003e Weak telltale, uneven impeller wear, creeping temps, or the engine running hot at idle.\u003c\/p\u003e\n\u003cp data-start=\"2316\" data-end=\"2456\"\u003e\u003cstrong data-start=\"2316\" data-end=\"2373\"\u003eQ2: Should I replace the impeller while I’m in there?\u003c\/strong\u003e\u003cbr data-start=\"2373\" data-end=\"2376\"\u003e\u003cstrong data-start=\"2376\" data-end=\"2382\"\u003eA:\u003c\/strong\u003e Yes—once the lower unit is off, it’s the perfect time to do the impeller.\u003c\/p\u003e\n\u003cp data-start=\"2458\" data-end=\"2569\"\u003e\u003cstrong data-start=\"2458\" data-end=\"2495\"\u003eQ3: Is this a do-it-yourself job?\u003c\/strong\u003e\u003cbr data-start=\"2495\" data-end=\"2498\"\u003e\u003cstrong data-start=\"2498\" data-end=\"2504\"\u003eA:\u003c\/strong\u003e If you’re comfortable dropping the lower unit, it’s very doable.\u003c\/p\u003e\n\u003cp data-start=\"2571\" data-end=\"2717\"\u003e\u003cstrong data-start=\"2571\" data-end=\"2622\"\u003eQ4: Will replacing the base help at higher RPM?\u003c\/strong\u003e\u003cbr data-start=\"2622\" data-end=\"2625\"\u003e\u003cstrong data-start=\"2625\" data-end=\"2631\"\u003eA:\u003c\/strong\u003e Definitely—if the pump can’t seal or catch water properly, it can’t keep up at speed.\u003c\/p\u003e\n\u003cp data-start=\"2719\" data-end=\"2858\"\u003e\u003cstrong data-start=\"2719\" data-end=\"2766\"\u003eQ5: How often should I check the pump base?\u003c\/strong\u003e\u003cbr data-start=\"2766\" data-end=\"2769\"\u003e\u003cstrong data-start=\"2769\" data-end=\"2775\"\u003eA:\u003c\/strong\u003e At least once a season, or anytime you’re already in there replacing the impeller.\u003c\/p\u003e","brand":"Mercury","offers":[{"title":"Default Title","offer_id":46940117500195,"sku":"46-42579A3","price":39.07,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0783\/7410\/9475\/files\/PV446868_4.jpg?v=1698811421","url":"https:\/\/partsvu.com\/en-mx\/products\/mercury-base-assy-w-p-46-42579a3","provider":"PartsVu","version":"1.0","type":"link"}