{"about":"Prices are for United Kingdom in GBP. Every URL here is a plain path you can fetch directly.","product":{"basketKey":"dbb23d2f2b61","name":"PISTON KIT 81MM YAMAHA WR/YZ 250 14-18, ATHENA S4F08100005B 276CC BIG BORE","sku":"56-K170.81.PIB","brand":"Athena","mpn":null,"gtin":null,"condition":"new","inStock":true,"stock":1,"price":{"amount":206.06,"formatted":"£206.06"},"summary":"Forged Racing Piston Ø 80.96 mm for Athena Big Bore Cylinder. Made from a special high-performance aluminum alloy with high silicon content. Features include cutting-edge CNC machining for precise tolerances, a smooth profile for regular flow and perfect flame propagation, and molybdenum disulfide coating on some skirts to reduce friction. Piston rings, produced in Japan with wear-resistant coatings, ensure less friction and higher performance. This kit contains the piston, pin, circlips, and piston rings. Technical features: Bore Diameter 80.96 mm, Compression Ratio 13.2:1, Displacement 250 cc, Number Of Segments 3, Piston Pin Type Standard, Piston Type Forged. Manufacturer part number S4F08100005B. Partner cross reference codes: S4F08100005A, S41316296.","attributes":[{"label":"General Product Group","value":"Engine"},{"label":"General Product Type","value":"Pistons & Kits"},{"label":"General Size","value":"81mm"},{"label":"Variant Id","value":"253033"}],"image":"https://b69270dd6ab1.blob.upstash.io/oracle/oro2u/56-K170_2E81_2EPIB/bca4e754541f39ed.jpg","images":["https://b69270dd6ab1.blob.upstash.io/oracle/oro2u/56-K170_2E81_2EPIB/bca4e754541f39ed.jpg"],"description":"Forged Racing Piston Ø 80.96 mm for Athena Big Bore Cylinder. Made from a special high-performance aluminum alloy with high silicon content. Features include cutting-edge CNC machining for precise tolerances, a smooth profile for regular flow and perfect flame propagation, and molybdenum disulfide coating on some skirts to reduce friction. Piston rings, produced in Japan with wear-resistant coatings, ensure less friction and higher performance. This kit contains the piston, pin, circlips, and piston rings. Technical features: Bore Diameter 80.96 mm, Compression Ratio 13.2:1, Displacement 250 cc, Number Of Segments 3, Piston Pin Type Standard, Piston Type Forged. Manufacturer part number S4F08100005B. Partner cross reference codes: S4F08100005A, S41316296.","descriptionMarkdown":"### Athena 276cc Big Bore Forged Piston Kit 81mm\n\nEnhance your motorcycle's performance with this high-quality forged piston kit from Athena. Engineered for demanding off-road applications, this kit is designed to provide superior reliability, durability, and power.\n\nAthena pistons are manufactured using advanced CNC machining tools, ensuring exceptional dimensional accuracy. Constructed from a specialized high-performance aluminum alloy with a high silicon content, these pistons offer robustness comparable to original equipment (OE) while delivering increased strength and improved performance.\n\nKey Features:\n\n \n- Forged Piston Construction: Offers greater strength and durability compared to cast pistons.\n \n- High-Performance Aluminum Alloy: Features high silicon content for excellent thermal resistance and strength.\n \n- Precision Machining: CNC machined to tolerances of less than 0.01 mm for a perfect fit and optimal performance.\n \n- Optimized Profile: Ensures smooth airflow and efficient flame propagation for better combustion.\n \n- Molybdenum Disulfide Coating: Some piston skirts are treated to reduce friction, further boosting performance and longevity.\n \n- High-Quality Piston Rings: Made in Japan with wear-resistant coatings (PVD or chromium nitride) for increased durability and reduced friction. Rings adapt well to the cylinder liner even at low tangential loads.\n \n- Complete Kit: Includes piston, pin, circlips, and piston rings. All components are replaceable and interchangeable.\n \n- Engineered and Tested in Italy: Developed by Athena's R&D department and rigorously tested on dynamometer benches and on track for validation under extreme conditions.\n\n**Technical Specifications:**\n\n \n- Bore Diameter: 80.96 mm\n \n- Displacement: 276 cc (Big Bore application)\n \n- Compression Ratio: 13.2:1\n \n- Piston Type: Forged\n \n- Number Of Segments: 3\n \n- Big End Pin Diameter: 16x10x42 mm\n \n- Piston Pin Type: Standard\n \n- Net Weight: 0.24 Kg\n\n**Note:** Products designed for increased displacement and power beyond road legal limits are intended exclusively for competitive use. Athena is not responsible for any use contrary to national regulations.","weightGrams":null,"fitments":[{"make":"YAMAHA","model":"WR 250F","cc":null,"notes":null,"years":"2015–2018"},{"make":"YAMAHA","model":"WR R 250","cc":null,"notes":null,"years":"2015–2016"},{"make":"YAMAHA","model":"WRF 250","cc":null,"notes":null,"years":"2015–2016"},{"make":"YAMAHA","model":"YZ 250F","cc":null,"notes":null,"years":"2014–2018"},{"make":"YAMAHA","model":"YZ 250FX","cc":null,"notes":null,"years":"2015–2017"},{"make":"YAMAHA","model":"YZF 250","cc":null,"notes":null,"years":"2014–2015"}],"collections":[{"name":"Engine","url":"https://www.2brosparts.com/api/agent/collection/GB/engine"},{"name":"Pistons & Kits","url":"https://www.2brosparts.com/api/agent/collection/GB/pistons-kits"}],"links":{"page":"https://www.2brosparts.com/products/piston-kit-81mm-yamaha-wryz-250-14-18-athena-s4f08100005b-276cc-big-bore","buyOneNow":"https://www.2brosparts.com/api/agent/checkout/GB/dbb23d2f2b61:1","basketWithThis":"https://www.2brosparts.com/api/agent/basket/GB/dbb23d2f2b61:1"}},"market":{"country":"GB","countryName":"United Kingdom","locale":"en-gb","currency":"GBP","exchangeRateFromGbp":1,"pricesIncludeUkVat":true,"checkoutTax":null,"delivery":[{"name":"Standard","description":"Orders £15.00–£59.99 · 2–4 business days","carrier":null,"estimatedDays":"2–4 business days","price":{"amount":4.99,"formatted":"£4.99"},"free":false,"minimumOrder":{"amount":0,"formatted":"£0.00","gbp":0},"weightGrams":null},{"name":"Standard","description":"Orders £60.00 and up · 2–4 business days","carrier":null,"estimatedDays":"2–4 business days","price":{"amount":0,"formatted":"£0.00"},"free":true,"minimumOrder":{"amount":60,"formatted":"£60.00","gbp":60},"weightGrams":null}],"storeUrl":"https://www.2brosparts.com"},"navigate":{"start":"https://www.2brosparts.com/api/agent","search":"https://www.2brosparts.com/api/agent/search/GB/{words+joined+with+plus}"},"howToBuy":{"summary":"Build a basket for the shopper and give them one checkout link. Every URL is a plain path (no query string) and a GET. Nothing is stored between calls.","checkoutLinkFormat":"https://www.2brosparts.com/api/agent/checkout/GB/{basketKey}:{quantity},{basketKey}:{quantity}","steps":["1. Find products: follow links in these responses, or fetch https://www.2brosparts.com/api/agent/search/GB/{words+joined+with+plus} (e.g. https://www.2brosparts.com/api/agent/search/GB/brake+pads). Every product has a basketKey.","2. Optional check: https://www.2brosparts.com/api/agent/basket/GB/{basketKey}:{quantity},{basketKey}:{quantity} returns stock, totals per delivery option and the checkout link.","3. Give the shopper the checkout link. Opening it fills their basket with exactly these items (replacing what was there) and opens checkout for United Kingdom. They pay on 2brosparts.com through Stripe."],"noFetchNeeded":"You can write the checkout link yourself from basketKeys and quantities; nothing has to be fetched first. Each product also has links.buyOneNow, a ready link for one unit.","stateless":"Nothing is saved on our side. The items part of the URL is the whole basket: to change it, write the link again with the new list.","itemsFormat":"basketKey:quantity pairs joined by commas, e.g. 04f24aad4d68:2,7c1e9a0b3f2d:1. Quantity defaults to 1. Up to 50 products, 100 each.","country":"GB is the shopper's delivery country. Swap it for theirs (US, DE, FR…) in any URL; currency, tax and delivery follow it.","tips":["Put everything the shopper wants in one link.","Optionally add your name as a last path segment on checkout links (…/checkout/GB/<items>/claude) so the sale is credited to you.","The checkout link is for the shopper's browser. Do not open it yourself.","Signed-in trade account holders see their trade prices at checkout."]}}