{"product_id":"stihl-ring-4243-642-8201","title":"STIHL Ring -  4243 642 8201","description":"\u003cdiv\u003e\n\u003ch2\u003eKey Features\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003eOEM-manufactured sealing ring engineered to STIHL dimensional tolerances for pressurized fuel system integrity.\u003c\/li\u003e\n\u003cli\u003eSynthetic elastomer compound formulated to resist chemical breakdown from E10 gasoline and 50:1 two-stroke oil formulations.\u003c\/li\u003e\n\u003cli\u003ePrecision-controlled cross-section maintains uniform compression force, preventing vacuum leaks that cause lean-running engine conditions.\u003c\/li\u003e\n\u003cli\u003eDirect mechanical replacement eliminates adapter hardware or machining during routine maintenance sequences.\u003c\/li\u003e\n\u003c\/ul\u003e \u003ch2\u003eProduct Details\u003c\/h2\u003e\n\u003cp\u003eThis genuine STIHL replacement ring is engineered for high-pressure fluid interfaces within carburetor assemblies, fuel pump housings, and cylinder base mating surfaces. The component utilizes a hydrocarbon-stabilized synthetic rubber matrix to prevent accelerated hardening when exposed to modern oxygenated fuel blends. Designed for continuous cyclic compression, the ring retains elastic recovery across standard operating temperature ranges and provides reliable long-term sealing against fuel vapor migration. Installation follows manufacturer torque specifications and surface preparation guidelines detailed in the corresponding operator service manual.\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eManufacturer part designation: 4243 642 8201\u003c\/li\u003e\n\u003cli\u003eMaterial classification: Sulfur-free synthetic elastomer rated for petroleum-based hydraulic and fuel environments\u003c\/li\u003e\n\u003cli\u003ePrimary application zones: Carburetor flange gaskets, fuel line pressure couplings, pump diaphragm chamber seals\u003c\/li\u003e\n\u003cli\u003eManufacturing protocol: Produced under STIHL quality assurance standards matching original equipment assembly specifications\u003c\/li\u003e\n\u003c\/ul\u003e \u003ch2\u003eCompatibility\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003eMS 250, MS 251, MS 261 chainsaw series\u003c\/li\u003e\n\u003cli\u003eMS 361, MS 391 professional chainsaw platforms\u003c\/li\u003e\n\u003cli\u003eFS 38, FS 40, FS 46, FS 56 brushcutter variants\u003c\/li\u003e\n\u003cli\u003eKMV 56, K 56 cut-off machine engine blocks\u003c\/li\u003e\n\u003cli\u003eSR 400 leaf blower intake assemblies\u003c\/li\u003e\n\u003cli\u003eIntegrates with complete gasket kit replacements bearing part codes 4243 700 21XX through 4243 700 34XX where factory ring substitution is documented\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/div\u003e","brand":"STIHL","offers":[{"title":"Default Title","offer_id":58571555111293,"sku":"ST-4243 642 8201","price":2.42,"currency_code":"GBP","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0565\/9190\/9056\/files\/4243-642-8201.jpg?v=1787321332","url":"https:\/\/ripongroundcare.com\/products\/stihl-ring-4243-642-8201","provider":"Ripon Ground Care","version":"1.0","type":"link"}