{"product_id":"sierra-18-3081-neoprene-impeller-kit-volvo-penta-3862281","title":"Sierra 18-3081 Neoprene Impeller Kit | 12-Fin 12-Spline | Volvo Penta 3862281 \/ Johnson 09-1027B","description":"\u003ch2\u003eSierra 18-3081 Neoprene Impeller Kit\u003c\/h2\u003e\n\u003cp\u003e\u003cstrong\u003ePart Number:\u003c\/strong\u003e 18-3081 (Sierra)  |  \u003cstrong\u003eCatalog Number:\u003c\/strong\u003e 47-3081  |  \u003cstrong\u003eBrand:\u003c\/strong\u003e Sierra\u003c\/p\u003e\n\u003cp\u003eSierra \u003cstrong\u003e18-3081\u003c\/strong\u003e is a 12-fin neoprene flexible impeller kit for selected Volvo Penta, OMC, Johnson Pump, and Jabsco raw-water pump applications. It restores proper seawater circulation when the original impeller has become worn, hardened, cracked, or damaged.\u003c\/p\u003e\n\u003cp\u003eThe impeller uses a \u003cstrong\u003e12-spline brass hub\u003c\/strong\u003e and measures approximately \u003cstrong\u003e2.255 in. \/ 57.3 mm outside diameter\u003c\/strong\u003e and \u003cstrong\u003e1.243 in. \/ 31.6 mm wide\u003c\/strong\u003e. The 12-spline hub is a key fitment identifier — several other 12-blade impellers in the same diameter range use different hub configurations and are not interchangeable.\u003c\/p\u003e\n\n\u003ch2\u003eSpecifications\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eManufacturer Part Number:\u003c\/strong\u003e 18-3081\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCatalog \/ Item Number:\u003c\/strong\u003e 47-3081\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eBrand:\u003c\/strong\u003e Sierra\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eProduct Type:\u003c\/strong\u003e Flexible Impeller Kit\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMaterial:\u003c\/strong\u003e Neoprene\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFins \/ Blades:\u003c\/strong\u003e 12\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eHub Drive:\u003c\/strong\u003e 12-spline brass\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOutside Diameter:\u003c\/strong\u003e approx. 2.255 in. \/ 57.3 mm\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWidth:\u003c\/strong\u003e approx. 1.243 in. \/ 31.6 mm\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eBore:\u003c\/strong\u003e approx. 0.525 in. \/ 13.3 mm\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSystem:\u003c\/strong\u003e Marine engine raw-water (seawater) cooling pump\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eUPC:\u003c\/strong\u003e 030999315335\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2\u003eCompatible Applications\u003c\/h2\u003e\n\u003cp\u003eFitment is determined by the installed pump model or existing impeller number — not engine displacement alone. Confirmed cross-references:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eVolvo Penta \u003cstrong\u003e875811-2\u003c\/strong\u003e\n\u003c\/li\u003e\n\u003cli\u003eVolvo Penta \u003cstrong\u003e3858256\u003c\/strong\u003e\n\u003c\/li\u003e\n\u003cli\u003eVolvo Penta \u003cstrong\u003e3862281\u003c\/strong\u003e\n\u003c\/li\u003e\n\u003cli\u003eVolvo Penta \u003cstrong\u003e21951346\u003c\/strong\u003e\n\u003c\/li\u003e\n\u003cli\u003eVolvo Penta \u003cstrong\u003e24715100\u003c\/strong\u003e\n\u003c\/li\u003e\n\u003cli\u003eOMC \u003cstrong\u003e3858256\u003c\/strong\u003e\n\u003c\/li\u003e\n\u003cli\u003eJohnson Pump \u003cstrong\u003e09-1027B\u003c\/strong\u003e\n\u003c\/li\u003e\n\u003cli\u003eJohnson Pump \u003cstrong\u003e09-1027B-9\u003c\/strong\u003e\n\u003c\/li\u003e\n\u003cli\u003eJabsco \u003cstrong\u003e1210-0001\u003c\/strong\u003e\n\u003c\/li\u003e\n\u003cli\u003eJabsco \u003cstrong\u003e1210-0003\u003c\/strong\u003e\n\u003c\/li\u003e\n\u003cli\u003eSierra \u003cstrong\u003e18-3586\u003c\/strong\u003e raw-water pump applications\u003c\/li\u003e\n\u003cli\u003eGLM \u003cstrong\u003e89540\u003c\/strong\u003e\n\u003c\/li\u003e\n\u003cli\u003eMallory \u003cstrong\u003e9-45703\u003c\/strong\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003eThis impeller is used across a broad range of Volvo Penta gasoline and diesel installations — AQ-series through 3.0L, 4.3L, 5.0L, 5.7L, 7.4L, 8.1L, and selected diesel applications — but the installed pump number is the most reliable fitment reference.\u003c\/p\u003e\n\n\u003ch2\u003eFitment Notice\u003c\/h2\u003e\n\u003cp\u003eBefore ordering, confirm all of the following:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e12 fins \/ blades\u003c\/li\u003e\n\u003cli\u003eHub drive: \u003cstrong\u003e12-spline\u003c\/strong\u003e (not keyed or single-flat)\u003c\/li\u003e\n\u003cli\u003eOutside diameter: approx. \u003cstrong\u003e2.255 in. \/ 57.3 mm\u003c\/strong\u003e\n\u003c\/li\u003e\n\u003cli\u003eWidth: approx. \u003cstrong\u003e1.243 in. \/ 31.6 mm\u003c\/strong\u003e\n\u003c\/li\u003e\n\u003cli\u003eOriginal reference matches one of the cross-reference numbers above\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003eDo not confuse this impeller with the wider \u003cstrong\u003eJohnson Pump 09-812B \/ Jabsco 13554-0001\u003c\/strong\u003e design — both have 12 blades and a splined hub but differ in width and pump application and are not interchangeable.\u003c\/p\u003e\n\u003cp\u003eSome pump arrangements associated with Volvo Penta \u003cstrong\u003e3862281\u003c\/strong\u003e use a three-bolt cover with a specific gasket. Confirm your pump’s cover and gasket configuration before disassembly and source the correct sealing components for your pump.\u003c\/p\u003e\n\n\u003ch2\u003eService Interval\u003c\/h2\u003e\n\u003cp\u003eInspect the impeller at each annual cooling-system service. Replace immediately when any of the following are observed:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eReduced or absent raw-water flow at the exhaust outlet\u003c\/li\u003e\n\u003cli\u003eEngine running hotter than normal\u003c\/li\u003e\n\u003cli\u003ePump slow to prime or fails to prime\u003c\/li\u003e\n\u003cli\u003eBlades cracked, torn, hardened, or permanently set\u003c\/li\u003e\n\u003cli\u003eBlade tips missing — inspect all downstream hoses, heat exchangers, and oil coolers before fitting the replacement\u003c\/li\u003e\n\u003cli\u003ePump has operated dry (replace immediately)\u003c\/li\u003e\n\u003cli\u003eService history is unknown\u003c\/li\u003e\n\u003cli\u003eAnnual service interval or 500–1,000 operating hours reached, whichever comes first\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2\u003eInstallation Notes\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003eShut down the engine and disconnect the battery\u003c\/li\u003e\n\u003cli\u003eClose the raw-water intake seacock\u003c\/li\u003e\n\u003cli\u003eNote the pump cover and gasket arrangement before disassembly — the 3862281 pump family uses a specific three-bolt cover in some installations\u003c\/li\u003e\n\u003cli\u003eRemove the old impeller carefully without scoring the pump housing bore\u003c\/li\u003e\n\u003cli\u003eInspect the cover plate, cam surface, shaft, and pump body for wear or scoring\u003c\/li\u003e\n\u003cli\u003eLocate and recover all missing blade pieces before installing the new impeller\u003c\/li\u003e\n\u003cli\u003eLubricate the replacement impeller with glycerin or dish soap — do not use petroleum-based lubricants\u003c\/li\u003e\n\u003cli\u003eAlign the 12-spline hub with the pump shaft and press the impeller fully into the bore\u003c\/li\u003e\n\u003cli\u003eInstall the correct gasket or O-ring for the specific pump\u003c\/li\u003e\n\u003cli\u003eTighten cover fasteners evenly\u003c\/li\u003e\n\u003cli\u003eOpen the seacock and verify strong water flow at the exhaust immediately after startup\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2\u003eCross-Reference Part Numbers\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eSierra:\u003c\/strong\u003e 18-3081\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCatalog ref:\u003c\/strong\u003e 47-3081\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eVolvo Penta:\u003c\/strong\u003e 875811-2\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eVolvo Penta:\u003c\/strong\u003e 3858256\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eVolvo Penta:\u003c\/strong\u003e 3862281\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eVolvo Penta:\u003c\/strong\u003e 21951346\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eVolvo Penta (current ref):\u003c\/strong\u003e 24715100\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOMC:\u003c\/strong\u003e 3858256\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eJohnson Pump:\u003c\/strong\u003e 09-1027B\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eJohnson Pump:\u003c\/strong\u003e 09-1027B-9\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eJabsco:\u003c\/strong\u003e 1210-0001\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eJabsco:\u003c\/strong\u003e 1210-0003\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eGLM:\u003c\/strong\u003e 89540\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMallory:\u003c\/strong\u003e 9-45703\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eUPC:\u003c\/strong\u003e 030999315335\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2\u003eRelated Products\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003ca href=\"\/products\/11110181044260\"\u003eJabsco 1210-0001-P Neoprene Impeller Kit\u003c\/a\u003e — Jabsco OEM equivalent for this impeller family\u003c\/li\u003e\n\u003cli\u003e\n\u003ca href=\"\/products\/11110181077028\"\u003eJabsco 1210-0003-P Nitrile Impeller Kit\u003c\/a\u003e — nitrile compound alternative for the same pump family\u003c\/li\u003e\n\u003cli\u003e\n\u003ca href=\"\/products\/11110179668004\"\u003eJohnson Pump F5B Impeller Kit 09-1027B-1\u003c\/a\u003e — Johnson Pump OEM service kit for F5B \/ 09-1027B applications\u003c\/li\u003e\n\u003cli\u003e\n\u003ca href=\"\/products\/11110179700772\"\u003eJohnson Pump 09-1027B-10 Impeller | Volvo Penta F5B-9\u003c\/a\u003e — F5B-9 variant\u003c\/li\u003e\n\u003cli\u003e\n\u003ca href=\"\/products\/11110180552740\"\u003eARCO IP002 Volvo Penta Raw Water Pump Impeller | Replaces 21951346 \/ 3862281\u003c\/a\u003e — ARCO aftermarket alternative for the same Volvo Penta cross-reference family\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2\u003eParts Desk Insights\u003c\/h2\u003e\n\u003cp\u003e\u003cstrong\u003eBest use case:\u003c\/strong\u003e Sierra 18-3081 is the standard annual-service impeller for Volvo Penta raw-water pump applications in the \u003cstrong\u003e3858256 \/ 3862281 \/ 21951346 \/ 24715100\u003c\/strong\u003e supersession chain, and for any Johnson Pump F5B or Jabsco 1210-series pump. It’s one of the most widely stocked impellers in the Volvo Penta aftermarket, making it a reliable choice when OEM lead times are an issue.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eCommon issues:\u003c\/strong\u003e The most frequent ordering mistake is selecting by diameter alone. The \u003cstrong\u003e12-spline hub and 1.243 in. \/ 31.6 mm width\u003c\/strong\u003e are the critical differentiators — there are visually similar impellers with the same blade count but different widths or hub styles that will not fit this pump family. Always confirm against one of the OEM cross-reference numbers above. If blade pieces are missing after removal, don’t assume they came out with the impeller — trace every downstream passage including thermostat housing, oil cooler, and heat exchanger before installing the new impeller.\u003c\/p\u003e","brand":"LNS","offers":[{"title":"Default Title","offer_id":51156140326948,"sku":"47-3081","price":52.89,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0743\/5799\/7604\/files\/47-3081.jpg?v=1784926836","url":"https:\/\/marisolmarine.com\/products\/sierra-18-3081-neoprene-impeller-kit-volvo-penta-3862281","provider":"Marisol Marine Company","version":"1.0","type":"link"}