{"product_id":"seachoice-50-21021-full-flow-oil-filter-20-micron","title":"Seachoice 50-21021 Full-Flow Oil Filter – 20 Micron | Yanmar \u0026 Westerbeke Marine Diesel","description":"\u003csection class=\"product-description\"\u003e\n\n\u003ch2\u003eSeachoice 50-21021 Full-Flow Oil Filter – 20 Micron\u003c\/h2\u003e\n\u003cp\u003e\u003cstrong\u003ePart Number:\u003c\/strong\u003e 50-21021  |  \u003cstrong\u003eSKU:\u003c\/strong\u003e 50-21021  |  \u003cstrong\u003eUPC:\u003c\/strong\u003e 719249210216\u003c\/p\u003e\n\n\u003cp\u003eThe Seachoice 50-21021 is a 20-micron full-flow spin-on oil filter for compatible Yanmar and Westerbeke marine diesel engines. It crosses directly to Sierra 18-7910-1, Westerbeke 30220, and multiple Yanmar OEM filter numbers. Built with high-efficiency cellulose filter media, an epoxy-coated corrosion-resistant canister, reinforced body construction, heavy-duty end-cap seals, and an anti-drain-back valve, it meets or exceeds original equipment filtration requirements for applicable Yanmar and Westerbeke diesel applications.\u003c\/p\u003e\n\n\u003ch2\u003eKey Specifications\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003eFiltration: 20 micron\u003c\/li\u003e\n\u003cli\u003eFilter type: Full-flow spin-on\u003c\/li\u003e\n\u003cli\u003eThread: 20 mm x 1.5\u003c\/li\u003e\n\u003cli\u003eFilter media: High-efficiency cellulose\u003c\/li\u003e\n\u003cli\u003eAnti-drain-back valve: Yes\u003c\/li\u003e\n\u003cli\u003eCanister: Epoxy-coated steel for corrosion resistance\u003c\/li\u003e\n\u003cli\u003eBody: Reinforced construction\u003c\/li\u003e\n\u003cli\u003eEnd-cap seals: Heavy-duty\u003c\/li\u003e\n\u003cli\u003eManufactured in an ISO\/TS 16949 certified facility\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2\u003eCompatible Applications\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003eYanmar 1GM marine diesel engines\u003c\/li\u003e\n\u003cli\u003eYanmar 1GM10 marine diesel engines\u003c\/li\u003e\n\u003cli\u003eYanmar 2GM marine diesel engines\u003c\/li\u003e\n\u003cli\u003eYanmar 2GMF marine diesel engines\u003c\/li\u003e\n\u003cli\u003eYanmar 2GM20 marine diesel engines\u003c\/li\u003e\n\u003cli\u003eYanmar 2GM20F marine diesel engines\u003c\/li\u003e\n\u003cli\u003eYanmar 3GM marine diesel engines\u003c\/li\u003e\n\u003cli\u003eYanmar 3GMF marine diesel engines\u003c\/li\u003e\n\u003cli\u003eYanmar 3GM30 marine diesel engines\u003c\/li\u003e\n\u003cli\u003eYanmar 3GM30F marine diesel engines\u003c\/li\u003e\n\u003cli\u003eWesterbeke marine diesel engines specifying Westerbeke 30220 or Sierra 18-7910-1\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003e\u003cem\u003e\u003cstrong\u003eFitment Note:\u003c\/strong\u003e Confirm your engine model and existing filter part number before ordering. The 20 mm x 1.5 thread and cross-reference to Yanmar 124450-35100 or Westerbeke 30220 are the most reliable fitment identifiers. Match by part number rather than appearance alone.\u003c\/em\u003e\u003c\/p\u003e\n\n\u003ch2\u003eService Interval\u003c\/h2\u003e\n\u003cp\u003eReplace at every scheduled engine oil service. Marine diesel engines typically require more frequent oil and filter changes than gasoline engines — follow the engine manufacturer’s recommended service interval for your specific Yanmar or Westerbeke model. Refer to your engine service manual for guidance.\u003c\/p\u003e\n\n\u003ch2\u003eInstallation Notes\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003eRemove the old filter and confirm the old gasket has come away with it — a retained gasket will cause an oil leak\u003c\/li\u003e\n\u003cli\u003eClean the filter mounting surface\u003c\/li\u003e\n\u003cli\u003eLightly coat the new filter gasket with fresh engine oil before threading it on\u003c\/li\u003e\n\u003cli\u003eTighten by hand plus ¾ turn, or per engine manufacturer specification — do not over-tighten\u003c\/li\u003e\n\u003cli\u003eRun the engine and inspect for leaks before returning to service\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\u003eSeachoice:\u003c\/strong\u003e 50-21021 \/ 21021\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSierra:\u003c\/strong\u003e 18-7910-1\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWesterbeke:\u003c\/strong\u003e 30220\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eYanmar:\u003c\/strong\u003e 124450-35100, 119350-35150, 119350-35151, 119660-35150\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMallory:\u003c\/strong\u003e 9-57810\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\/sierra-47-237800-oil-filter-westerbeke-marine-diesel-engine\"\u003eSierra 47-237800 Oil Filter – Westerbeke Marine Diesel Engine\u003c\/a\u003e — Sierra diesel filter for Westerbeke applications\u003c\/li\u003e\n\u003cli\u003e\n\u003ca href=\"\/products\/sierra-18-7884-diesel-oil-filter\"\u003eSierra 18-7884 Diesel Oil Filter – Universal \u0026amp; Volvo Penta Marine Diesel\u003c\/a\u003e — alternate marine diesel oil filter\u003c\/li\u003e\n\u003cli\u003e\n\u003ca href=\"\/products\/sierra-79101-diesel-oil-filter-47-79101\"\u003eSierra 79101 Diesel Oil Filter\u003c\/a\u003e — alternate Sierra marine diesel filter\u003c\/li\u003e\n\u003cli\u003e\u003ca href=\"\/products\/sierra-oil-drain-kit-1-2-20-thread-42-length-47-7891\"\u003eSierra Oil Drain Kit – 1\/2\"-20 Thread, 42\" Length (47-7891)\u003c\/a\u003e\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 Routine oil and filter changes on Yanmar 1GM, 2GM, and 3GM-series marine diesel engines — some of the most common compact diesel auxiliaries found on sailboats and small trawlers — as well as compatible Westerbeke diesel applications. Diesel engine oil services tend to come around more frequently than gasoline equivalents, making this a high-turnover maintenance item for shops serving sailboat and trawler owners.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eCommon Issues:\u003c\/strong\u003e Yanmar uses multiple filter part numbers across their GM-series engine families, and several filters look similar. The safest confirmation is matching Yanmar 124450-35100 or Sierra 18-7910-1 against the engine’s service records or existing filter. The 20 mm x 1.5 thread is also a useful cross-check. Always remind customers to verify the old gasket came off with the old filter before installing the new one — a double gasket on the mount is a common source of post-service oil leaks on these small diesels.\u003c\/p\u003e\n\n\u003c\/section\u003e","brand":"LNS","offers":[{"title":"Default Title","offer_id":51199649251364,"sku":"50-21021","price":19.59,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0743\/5799\/7604\/files\/50-21017_Main_fe57e37c-0f00-4485-af88-9f8bcda4cff5.jpg?v=1785611144","url":"https:\/\/marisolmarine.com\/products\/seachoice-50-21021-full-flow-oil-filter-20-micron","provider":"Marisol Marine Company","version":"1.0","type":"link"}