{"about":"Prices are for United Kingdom in GBP. Every URL here is a plain path you can fetch directly.","product":{"basketKey":"a23d70bbb7c8","name":"CYLINDER FULL KIT 58mm YAMAHA YZ 125 22-26, ATHENA P400485100101 BIG BORE, (Piston included)","sku":"56-K1993.58.CKA.BB","brand":"Athena","mpn":null,"gtin":null,"condition":"new","inStock":true,"stock":1,"price":{"amount":963.6,"formatted":"£963.60"},"summary":"Athena Big Bore Cylinder Kit for Yamaha YZ 125 models. This kit increases displacement to 144cc with a 58mm bore diameter and a 15.4:1 compression ratio. Features an aluminum cylinder with optimized geometries, intake, and exhaust ports for efficient combustion and optimal gas flow. Includes a modular head with an aluminum outer shell and bronze inner dome for customizable squish and compression ratios, improved heat dissipation, and increased reliability. The exhaust power valves are made from Ergal 7075 with hard anodizing for high temperature resistance and durability. The kit includes a high-quality gasket set for complete installation.","attributes":[],"image":"https://b69270dd6ab1.blob.upstash.io/oracle/oro2u/56-K1993_2E58_2ECKA_2EBB/b8b6a057134ed836.jpg","images":["https://b69270dd6ab1.blob.upstash.io/oracle/oro2u/56-K1993_2E58_2ECKA_2EBB/b8b6a057134ed836.jpg"],"description":"Athena Big Bore Cylinder Kit for Yamaha YZ 125 models. This kit increases displacement to 144cc with a 58mm bore diameter and a 15.4:1 compression ratio. Features an aluminum cylinder with optimized geometries, intake, and exhaust ports for efficient combustion and optimal gas flow. Includes a modular head with an aluminum outer shell and bronze inner dome for customizable squish and compression ratios, improved heat dissipation, and increased reliability. The exhaust power valves are made from Ergal 7075 with hard anodizing for high temperature resistance and durability. The kit includes a high-quality gasket set for complete installation.","descriptionMarkdown":"### Athena Big Bore Cylinder Kit 58mm for Yamaha YZ 125\n\nElevate your Yamaha YZ 125 with the Athena Big Bore Cylinder Kit, engineered to maximize power and track performance. This kit transforms your standard bore cylinder into a high-performance 144cc powerhouse, delivering a surge of power from the first twist of the throttle.\n\nExperience advanced technology designed for superior performance. The aluminum cylinder features optimized geometries for combustion efficiency, with intake and exhaust ports designed for optimal gas flow. Large water jackets are tailored to prevent overheating during demanding sessions, ensuring smooth and balanced power delivery across the entire RPM range.\n\nThe modular cylinder head boasts an aluminum outer shell and a bronze inner dome, allowing for customization of squish and compression ratios. This innovative design enhances heat dissipation, increases reliability, and extends engine life, especially under extreme off-road conditions. The self-centering dome ensures a perfect seal and optimal combustion for smooth and consistent power.\n\nDurable and reliable exhaust power valves, constructed from Ergal 7075 with hard anodizing, offer resistance to high temperatures while remaining lightweight. Precisely engineered, these valves ensure an airtight seal, preventing compression losses and maintaining combustion efficiency for consistent power delivery.\n\nThis complete kit includes a high-quality gasket set, designed for a perfect installation and engineered to withstand extreme track conditions, ensuring a perfect seal and long engine life.\n\n**Key Features:**\n\n \n- Increases displacement to 144cc\n \n- Aluminum cylinder with optimized geometries for combustion efficiency\n \n- Optimized intake and exhaust ports for maximum gas flow\n \n- Large water jackets to prevent overheating\n \n- Modular cylinder head with customizable squish and compression ratios\n \n- Bronze inner dome for improved heat dissipation and reliability\n \n- Ergal 7075 exhaust power valves with hard anodizing\n \n- Complete kit including high-quality gasket set\n\n**Specifications:**\n\n \n- Bore Diameter: 58 mm\n \n- Displacement: 144 cc\n \n- Compression Ratio: 15.4:1","weightGrams":null,"fitments":[],"collections":[],"links":{"page":"https://www.2brosparts.com/products/cylinder-full-kit-58mm-yamaha-yz-125-22-26-athena-p400485100101-big-bore-piston-","buyOneNow":"https://www.2brosparts.com/api/agent/checkout/GB/a23d70bbb7c8:1","basketWithThis":"https://www.2brosparts.com/api/agent/basket/GB/a23d70bbb7c8:1"}},"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."]}}