{"title":"REFURBISHED OEM STEEL SLEEVED BLOCKS","description":"","products":[{"product_id":"reconditioned-74mm-steel-sleeve-cylinder-block-for-2088-2013-raptor-250","title":"RECONDITIONED 74mm STEEL SLEEVE CYLINDER BLOCK FOR 2008-2013 RAPTOR 250","description":"\u003cp class=\"MsoNormal\" align=\"center\" style=\"mso-margin-top-alt: auto; mso-margin-bottom-alt: auto; text-align: center; line-height: normal; mso-outline-level: 2;\"\u003e\u003cb\u003e\u003cspan style=\"font-size: 18.0pt; font-family: 'Times New Roman',serif; mso-fareast-font-family: 'Times New Roman'; color: black; mso-font-kerning: 0pt; mso-ligatures: none;\"\u003eRESLEEVED OEM YAMAHA BLOCK\u003c\/span\u003e\u003c\/b\u003e\u003cb\u003e\u003cspan style=\"font-size: 18.0pt; font-family: 'Times New Roman',serif; mso-fareast-font-family: 'Times New Roman'; mso-font-kerning: 0pt; mso-ligatures: none;\"\u003e\u003c\/span\u003e\u003c\/b\u003e\u003c\/p\u003e\n\u003cp style=\"mso-margin-bottom-alt: auto; line-height: normal;\" class=\"MsoNormal\"\u003e\u003cspan style=\"font-family: 'Arial',sans-serif; mso-fareast-font-family: 'Times New Roman'; mso-font-kerning: 0pt; mso-ligatures: none;\"\u003eThe transition from a high-performance Nikasil-plated cylinder to a traditional steel sleeve is a common \"reliability-first\" overhaul. It transforms a specialized, thin-film coating into a robust, serviceable component.\u003c\/span\u003e\u003c\/p\u003e\n\u003cdiv style=\"margin-bottom: 0in; text-align: center; line-height: normal;\" align=\"center\" class=\"MsoNormal\"\u003e\u003chr align=\"center\" width=\"100%\" size=\"2\"\u003e\u003c\/div\u003e\n\u003cp style=\"mso-margin-bottom-alt: auto; line-height: normal; mso-outline-level: 2;\" class=\"MsoNormal\"\u003e\u003cb\u003e\u003cspan style=\"font-size: 18.0pt; font-family: 'Arial',sans-serif; mso-fareast-font-family: 'Times New Roman'; mso-font-kerning: 0pt; mso-ligatures: none;\"\u003eThe Reconditioning Process: Precision Surgery\u003c\/span\u003e\u003c\/b\u003e\u003c\/p\u003e\n\u003cp style=\"mso-margin-bottom-alt: auto; line-height: normal;\" class=\"MsoNormal\"\u003e\u003cspan style=\"font-family: 'Arial',sans-serif; mso-fareast-font-family: 'Times New Roman'; mso-font-kerning: 0pt; mso-ligatures: none;\"\u003eConverting an OEM aluminum block to a steel sleeve is a multi-step machining operation that requires surgical accuracy:\u003c\/span\u003e\u003c\/p\u003e\n\u003col type=\"1\" start=\"1\" style=\"margin-top: 0in;\"\u003e\n\u003cli style=\"mso-margin-bottom-alt: auto; line-height: normal; mso-list: l1 level1 lfo1; tab-stops: list .5in;\" class=\"MsoNormal\"\u003e\n\u003cb\u003e\u003cspan style=\"font-family: 'Arial',sans-serif; mso-fareast-font-family: 'Times New Roman'; mso-font-kerning: 0pt; mso-ligatures: none;\"\u003eBoring the Host:\u003c\/span\u003e\u003c\/b\u003e\u003cspan style=\"font-family: 'Arial',sans-serif; mso-fareast-font-family: 'Times New Roman'; mso-font-kerning: 0pt; mso-ligatures: none;\"\u003e The original cylinder is mounted on a boring bar or CNC mill. The Nikasil layer and a specific amount of the underlying aluminum are bored out to create a \"press-fit\" shoulder.\u003c\/span\u003e\n\u003c\/li\u003e\n\u003cli style=\"mso-margin-bottom-alt: auto; line-height: normal; mso-list: l1 level1 lfo1; tab-stops: list .5in;\" class=\"MsoNormal\"\u003e\n\u003cb\u003e\u003cspan style=\"font-family: 'Arial',sans-serif; mso-fareast-font-family: 'Times New Roman'; mso-font-kerning: 0pt; mso-ligatures: none;\"\u003eThermal Interference Fit:\u003c\/span\u003e\u003c\/b\u003e\u003cspan style=\"font-family: 'Arial',sans-serif; mso-fareast-font-family: 'Times New Roman'; mso-font-kerning: 0pt; mso-ligatures: none;\"\u003e To ensure the new sleeve never moves, the aluminum block is heated in an industrial oven to expand the bore, while the steel sleeve is often chilled in liquid nitrogen to shrink it. The sleeve is then pressed into the block.\u003c\/span\u003e\n\u003c\/li\u003e\n\u003cli style=\"mso-margin-bottom-alt: auto; line-height: normal; mso-list: l1 level1 lfo1; tab-stops: list .5in;\" class=\"MsoNormal\"\u003e\n\u003cb\u003e\u003cspan style=\"font-family: 'Arial',sans-serif; mso-fareast-font-family: 'Times New Roman'; mso-font-kerning: 0pt; mso-ligatures: none;\"\u003eDecking and Porting:\u003c\/span\u003e\u003c\/b\u003e\u003cspan style=\"font-family: 'Arial',sans-serif; mso-fareast-font-family: 'Times New Roman'; mso-font-kerning: 0pt; mso-ligatures: none;\"\u003e Once seated, the top of the sleeve is milled (decked) perfectly flush with the cylinder head surface. If it’s a two-stroke engine, the ports in the sleeve are manually blended to match the aluminum casting.\u003c\/span\u003e\n\u003c\/li\u003e\n\u003cli style=\"mso-margin-bottom-alt: auto; line-height: normal; mso-list: l1 level1 lfo1; tab-stops: list .5in;\" class=\"MsoNormal\"\u003e\n\u003cb\u003e\u003cspan style=\"font-family: 'Arial',sans-serif; mso-fareast-font-family: 'Times New Roman'; mso-font-kerning: 0pt; mso-ligatures: none;\"\u003eFinal Hone:\u003c\/span\u003e\u003c\/b\u003e\u003cspan style=\"font-family: 'Arial',sans-serif; mso-fareast-font-family: 'Times New Roman'; mso-font-kerning: 0pt; mso-ligatures: none;\"\u003e The sleeve is bored to just under the final size and then cross-hatch honed to the exact clearance required for the piston and ring set.\u003c\/span\u003e\n\u003c\/li\u003e\n\u003c\/ol\u003e\n\u003cdiv style=\"margin-bottom: 0in; text-align: center; line-height: normal;\" align=\"center\" class=\"MsoNormal\"\u003e\u003chr align=\"center\" width=\"100%\" size=\"2\"\u003e\u003c\/div\u003e\n\u003cp style=\"mso-margin-bottom-alt: auto; line-height: normal; mso-outline-level: 2;\" class=\"MsoNormal\"\u003e\u003cb\u003e\u003cspan style=\"font-size: 18.0pt; font-family: 'Arial',sans-serif; mso-fareast-font-family: 'Times New Roman'; mso-font-kerning: 0pt; mso-ligatures: none;\"\u003eWhy the Switch? The Advantages of Steel\u003c\/span\u003e\u003c\/b\u003e\u003c\/p\u003e\n\u003cp style=\"mso-margin-bottom-alt: auto; line-height: normal;\" class=\"MsoNormal\"\u003e\u003cspan style=\"font-family: 'Arial',sans-serif; mso-fareast-font-family: 'Times New Roman'; mso-font-kerning: 0pt; mso-ligatures: none;\"\u003eWhile Nikasil is prized for heat dissipation and low friction, steel sleeves offer practical, \"real-world\" benefits that many builders prefer for longevity and ease of maintenance.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp style=\"mso-margin-bottom-alt: auto; line-height: normal; mso-outline-level: 3;\" class=\"MsoNormal\"\u003e\u003cb\u003e\u003cspan style=\"font-size: 13.5pt; font-family: 'Arial',sans-serif; mso-fareast-font-family: 'Times New Roman'; mso-font-kerning: 0pt; mso-ligatures: none;\"\u003e1. Unlimited Serviceability (The \"One-and-Done\" Fix)\u003c\/span\u003e\u003c\/b\u003e\u003c\/p\u003e\n\u003cp style=\"mso-margin-bottom-alt: auto; line-height: normal;\" class=\"MsoNormal\"\u003e\u003cspan style=\"font-family: 'Arial',sans-serif; mso-fareast-font-family: 'Times New Roman'; mso-font-kerning: 0pt; mso-ligatures: none;\"\u003eNikasil is a coating only a few microns thick. If you \"cold seize\" the engine or ingest dirt, the coating is usually ruined, requiring the entire cylinder to be sent away for a costly and time-consuming stripping and replating process.\u003c\/span\u003e\u003c\/p\u003e\n\u003cul type=\"disc\" style=\"margin-top: 0in;\"\u003e\n\u003cli style=\"mso-margin-bottom-alt: auto; line-height: normal; mso-list: l0 level1 lfo2; tab-stops: list .5in;\" class=\"MsoNormal\"\u003e\n\u003cb\u003e\u003cspan style=\"font-family: 'Arial',sans-serif; mso-fareast-font-family: 'Times New Roman'; mso-font-kerning: 0pt; mso-ligatures: none;\"\u003eThe Steel Edge:\u003c\/span\u003e\u003c\/b\u003e\u003cspan style=\"font-family: 'Arial',sans-serif; mso-fareast-font-family: 'Times New Roman'; mso-font-kerning: 0pt; mso-ligatures: none;\"\u003e If a sleeved cylinder gets scratched, you simply bore it to the next \"oversize\" ($0.25\\text{mm}$, $0.50\\text{mm}$, etc.) and install a larger piston. You can often do this 4 or 5 times before needing a new sleeve.\u003c\/span\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp style=\"mso-margin-bottom-alt: auto; line-height: normal; mso-outline-level: 3;\" class=\"MsoNormal\"\u003e\u003cb\u003e\u003cspan style=\"font-size: 13.5pt; font-family: 'Arial',sans-serif; mso-fareast-font-family: 'Times New Roman'; mso-font-kerning: 0pt; mso-ligatures: none;\"\u003e2. Cost-Effectiveness\u003c\/span\u003e\u003c\/b\u003e\u003c\/p\u003e\n\u003cp style=\"mso-margin-bottom-alt: auto; line-height: normal;\" class=\"MsoNormal\"\u003e\u003cspan style=\"font-family: 'Arial',sans-serif; mso-fareast-font-family: 'Times New Roman'; mso-font-kerning: 0pt; mso-ligatures: none;\"\u003eReplating Nikasil often costs significantly more than a simple bore and hone job at a local machine shop. By switching to steel, you eliminate the need for specialized chemical plating facilities in future rebuilds.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp style=\"mso-margin-bottom-alt: auto; line-height: normal; mso-outline-level: 3;\" class=\"MsoNormal\"\u003e\u003cb\u003e\u003cspan style=\"font-size: 13.5pt; font-family: 'Arial',sans-serif; mso-fareast-font-family: 'Times New Roman'; mso-font-kerning: 0pt; mso-ligatures: none;\"\u003e3. Durability Against Contaminants\u003c\/span\u003e\u003c\/b\u003e\u003c\/p\u003e\n\u003cp style=\"mso-margin-bottom-alt: auto; line-height: normal;\" class=\"MsoNormal\"\u003e\u003cspan style=\"font-family: 'Arial',sans-serif; mso-fareast-font-family: 'Times New Roman'; mso-font-kerning: 0pt; mso-ligatures: none;\"\u003eNikasil is notoriously sensitive to poor fuel quality (specifically high sulfur content) and can flake or \"peel\" under extreme conditions or improper storage. Steel is a much more forgiving material that handles varying fuel grades and environmental moisture with classic resilience.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp style=\"mso-margin-bottom-alt: auto; line-height: normal; mso-outline-level: 3;\" class=\"MsoNormal\"\u003e\u003cb\u003e\u003cspan style=\"font-size: 13.5pt; font-family: 'Arial',sans-serif; mso-fareast-font-family: 'Times New Roman'; mso-font-kerning: 0pt; mso-ligatures: none;\"\u003e4. Customization and Big Bore Potential\u003c\/span\u003e\u003c\/b\u003e\u003c\/p\u003e\n\u003cp style=\"mso-margin-bottom-alt: auto; line-height: normal;\" class=\"MsoNormal\"\u003e\u003cspan style=\"font-family: 'Arial',sans-serif; mso-fareast-font-family: 'Times New Roman'; mso-font-kerning: 0pt; mso-ligatures: none;\"\u003eWhen converting to a sleeve, builders often take the opportunity to \"over-bore\" the block beyond what the factory plating would allow. This is the easiest path to increasing displacement for more low-end grunt.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp style=\"mso-margin-bottom-alt: auto; line-height: normal;\" class=\"MsoNormal\"\u003e\u003cb\u003e\u003cspan style=\"font-family: 'Arial',sans-serif; mso-fareast-font-family: 'Times New Roman'; mso-font-kerning: 0pt; mso-ligatures: none;\"\u003eNote:\u003c\/span\u003e\u003c\/b\u003e\u003cspan style=\"font-family: 'Arial',sans-serif; mso-fareast-font-family: 'Times New Roman'; mso-font-kerning: 0pt; mso-ligatures: none;\"\u003e While steel sleeves hold heat slightly longer than aluminum-backed Nikasil, for most recreational and woods-racing applications, the trade-off for \"bulletproof\" reliability and the ability to rebuild the engine in a single weekend is well worth it.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp class=\"MsoNormal\" style=\"mso-margin-top-alt: auto; mso-margin-bottom-alt: auto; line-height: normal; mso-outline-level: 3;\"\u003e\u003cb\u003e\u003cspan style=\"font-size: 13.5pt; font-family: 'Times New Roman',serif; mso-fareast-font-family: 'Times New Roman'; color: #ff2a00; mso-font-kerning: 0pt; mso-ligatures: none;\"\u003e**RECOMMENDED TO PAIR WITH WISECO 4951M07400 **\u003c\/span\u003e\u003c\/b\u003e\u003cb\u003e\u003cspan style=\"font-size: 13.5pt; font-family: 'Times New Roman',serif; mso-fareast-font-family: 'Times New Roman'; mso-font-kerning: 0pt; mso-ligatures: none;\"\u003e\u003c\/span\u003e\u003c\/b\u003e\u003c\/p\u003e","brand":"Zoom Zoom Parts","offers":[{"title":"Default Title","offer_id":49137010114783,"sku":"OEM RAPTOR 250 STEEL SLEEVED 74mm BLOCK ONLY","price":424.95,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0770\/0741\/files\/20260424_133047_21c7aecf-5f22-450c-b001-de253066b53b.jpg?v=1778603576"},{"product_id":"reconditioned-76mm-big-bore-steel-sleeve-cylinder-block-for-2088-2013-raptor-250","title":"RECONDITIONED 76mm BIG BORE STEEL SLEEVE CYLINDER BLOCK FOR 2008-2013 RAPTOR 250","description":"\u003cp class=\"MsoNormal\" align=\"center\"\u003e\u003cb\u003e\u003cspan\u003eRESLEEVED OEM YAMAHA BLOCK\u003c\/span\u003e\u003c\/b\u003e\u003cb\u003e\u003cspan\u003e\u003c\/span\u003e\u003c\/b\u003e\u003c\/p\u003e\n\u003cp class=\"MsoNormal\"\u003e\u003cspan\u003eThe transition from a high-performance Nikasil-plated cylinder to a traditional steel sleeve is a common \"reliability-first\" overhaul. It transforms a specialized, thin-film coating into a robust, serviceable component.\u003c\/span\u003e\u003c\/p\u003e\n\u003cdiv align=\"center\" class=\"MsoNormal\"\u003e\u003chr align=\"center\" width=\"100%\" size=\"2\"\u003e\u003c\/div\u003e\n\u003cp class=\"MsoNormal\"\u003e\u003cb\u003e\u003cspan\u003eThe Reconditioning Process: Precision Surgery\u003c\/span\u003e\u003c\/b\u003e\u003c\/p\u003e\n\u003cp class=\"MsoNormal\"\u003e\u003cspan\u003eConverting an OEM aluminum block to a steel sleeve is a multi-step machining operation that requires surgical accuracy:\u003c\/span\u003e\u003c\/p\u003e\n\u003col type=\"1\" start=\"1\"\u003e\n\u003cli class=\"MsoNormal\"\u003e\n\u003cb\u003e\u003cspan\u003eBoring the Host:\u003c\/span\u003e\u003c\/b\u003e\u003cspan\u003e The original cylinder is mounted on a boring bar or CNC mill. The Nikasil layer and a specific amount of the underlying aluminum are bored out to create a \"press-fit\" shoulder.\u003c\/span\u003e\n\u003c\/li\u003e\n\u003cli class=\"MsoNormal\"\u003e\n\u003cb\u003e\u003cspan\u003eThermal Interference Fit:\u003c\/span\u003e\u003c\/b\u003e\u003cspan\u003e To ensure the new sleeve never moves, the aluminum block is heated in an industrial oven to expand the bore, while the steel sleeve is often chilled in liquid nitrogen to shrink it. The sleeve is then pressed into the block.\u003c\/span\u003e\n\u003c\/li\u003e\n\u003cli class=\"MsoNormal\"\u003e\n\u003cb\u003e\u003cspan\u003eDecking and Porting:\u003c\/span\u003e\u003c\/b\u003e\u003cspan\u003e Once seated, the top of the sleeve is milled (decked) perfectly flush with the cylinder head surface. If it’s a two-stroke engine, the ports in the sleeve are manually blended to match the aluminum casting.\u003c\/span\u003e\n\u003c\/li\u003e\n\u003cli class=\"MsoNormal\"\u003e\n\u003cb\u003e\u003cspan\u003eFinal Hone:\u003c\/span\u003e\u003c\/b\u003e\u003cspan\u003e The sleeve is bored to just under the final size and then cross-hatch honed to the exact clearance required for the piston and ring set.\u003c\/span\u003e\n\u003c\/li\u003e\n\u003c\/ol\u003e\n\u003cdiv align=\"center\" class=\"MsoNormal\"\u003e\u003chr align=\"center\" width=\"100%\" size=\"2\"\u003e\u003c\/div\u003e\n\u003cp class=\"MsoNormal\"\u003e\u003cb\u003e\u003cspan\u003eWhy the Switch? The Advantages of Steel\u003c\/span\u003e\u003c\/b\u003e\u003c\/p\u003e\n\u003cp class=\"MsoNormal\"\u003e\u003cspan\u003eWhile Nikasil is prized for heat dissipation and low friction, steel sleeves offer practical, \"real-world\" benefits that many builders prefer for longevity and ease of maintenance.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp class=\"MsoNormal\"\u003e\u003cb\u003e\u003cspan\u003e1. Unlimited Serviceability (The \"One-and-Done\" Fix)\u003c\/span\u003e\u003c\/b\u003e\u003c\/p\u003e\n\u003cp class=\"MsoNormal\"\u003e\u003cspan\u003eNikasil is a coating only a few microns thick. If you \"cold seize\" the engine or ingest dirt, the coating is usually ruined, requiring the entire cylinder to be sent away for a costly and time-consuming stripping and replating process.\u003c\/span\u003e\u003c\/p\u003e\n\u003cul type=\"disc\"\u003e\n\u003cli class=\"MsoNormal\"\u003e\n\u003cb\u003e\u003cspan\u003eThe Steel Edge:\u003c\/span\u003e\u003c\/b\u003e\u003cspan\u003e If a sleeved cylinder gets scratched, you simply bore it to the next \"oversize\" ($0.25\\text{mm}$, $0.50\\text{mm}$, etc.) and install a larger piston. You can often do this 4 or 5 times before needing a new sleeve.\u003c\/span\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp class=\"MsoNormal\"\u003e\u003cb\u003e\u003cspan\u003e2. Cost-Effectiveness\u003c\/span\u003e\u003c\/b\u003e\u003c\/p\u003e\n\u003cp class=\"MsoNormal\"\u003e\u003cspan\u003eReplating Nikasil often costs significantly more than a simple bore and hone job at a local machine shop. By switching to steel, you eliminate the need for specialized chemical plating facilities in future rebuilds.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp class=\"MsoNormal\"\u003e\u003cb\u003e\u003cspan\u003e3. Durability Against Contaminants\u003c\/span\u003e\u003c\/b\u003e\u003c\/p\u003e\n\u003cp class=\"MsoNormal\"\u003e\u003cspan\u003eNikasil is notoriously sensitive to poor fuel quality (specifically high sulfur content) and can flake or \"peel\" under extreme conditions or improper storage. Steel is a much more forgiving material that handles varying fuel grades and environmental moisture with classic resilience.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp class=\"MsoNormal\"\u003e\u003cb\u003e\u003cspan\u003e4. Customization and Big Bore Potential\u003c\/span\u003e\u003c\/b\u003e\u003c\/p\u003e\n\u003cp class=\"MsoNormal\"\u003e\u003cspan\u003eWhen converting to a sleeve, builders often take the opportunity to \"over-bore\" the block beyond what the factory plating would allow. This is the easiest path to increasing displacement for more low-end grunt.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp class=\"MsoNormal\"\u003e\u003cb\u003e\u003cspan\u003eNote:\u003c\/span\u003e\u003c\/b\u003e\u003cspan\u003e While steel sleeves hold heat slightly longer than aluminum-backed Nikasil, for most recreational and woods-racing applications, the trade-off for \"bulletproof\" reliability and the ability to rebuild the engine in a single weekend is well worth it.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp class=\"MsoNormal\" style=\"text-align: center;\"\u003e\u003cspan style=\"color: rgb(255, 42, 0);\"\u003e\u003cb\u003e**RECOMMENDED TO PAIR WITH WISECO 40078M07600 **\u003c\/b\u003e\u003c\/span\u003e\u003c\/p\u003e","brand":"Zoom Zoom Parts","offers":[{"title":"Default Title","offer_id":49137664917727,"sku":"OEM RAPTOR 250 STEEL SLEEVED 76mm BLOCK ONLY","price":424.95,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0770\/0741\/files\/20260424_135718_7a392945-245b-425d-b19e-236e9fee99f9.jpg?v=1778604558"},{"product_id":"reconditioned-94mm-stock-bore-steel-sleeve-cylinder-block-for-2004-2005-honda-trx450r","title":"RECONDITIONED 94mm STOCK BORE STEEL SLEEVE CYLINDER BLOCK FOR 2004-2005 HONDA TRX450R","description":"\u003cp class=\"MsoNormal\" align=\"center\"\u003e\u003cb\u003e\u003cspan\u003eRESLEEVED OEM HONDA BLOCK\u003c\/span\u003e\u003c\/b\u003e\u003cb\u003e\u003cspan\u003e\u003c\/span\u003e\u003c\/b\u003e\u003c\/p\u003e\n\u003cp class=\"MsoNormal\"\u003e\u003cspan\u003eThe transition from a high-performance Nikasil-plated cylinder to a traditional steel sleeve is a common \"reliability-first\" overhaul. It transforms a specialized, thin-film coating into a robust, serviceable component.\u003c\/span\u003e\u003c\/p\u003e\n\u003cdiv align=\"center\" class=\"MsoNormal\"\u003e\u003chr align=\"center\" width=\"100%\" size=\"2\"\u003e\u003c\/div\u003e\n\u003cp class=\"MsoNormal\"\u003e\u003cb\u003e\u003cspan\u003eThe Reconditioning Process: Precision Surgery\u003c\/span\u003e\u003c\/b\u003e\u003c\/p\u003e\n\u003cp class=\"MsoNormal\"\u003e\u003cspan\u003eConverting an OEM aluminum block to a steel sleeve is a multi-step machining operation that requires surgical accuracy:\u003c\/span\u003e\u003c\/p\u003e\n\u003col type=\"1\" start=\"1\"\u003e\n\u003cli class=\"MsoNormal\"\u003e\n\u003cb\u003e\u003cspan\u003eBoring the Host:\u003c\/span\u003e\u003c\/b\u003e\u003cspan\u003e The original cylinder is mounted on a boring bar or CNC mill. The Nikasil layer and a specific amount of the underlying aluminum are bored out to create a \"press-fit\" shoulder.\u003c\/span\u003e\n\u003c\/li\u003e\n\u003cli class=\"MsoNormal\"\u003e\n\u003cb\u003e\u003cspan\u003eThermal Interference Fit:\u003c\/span\u003e\u003c\/b\u003e\u003cspan\u003e To ensure the new sleeve never moves, the aluminum block is heated in an industrial oven to expand the bore, while the steel sleeve is often chilled in liquid nitrogen to shrink it. The sleeve is then pressed into the block.\u003c\/span\u003e\n\u003c\/li\u003e\n\u003cli class=\"MsoNormal\"\u003e\n\u003cb\u003e\u003cspan\u003eDecking and Porting:\u003c\/span\u003e\u003c\/b\u003e\u003cspan\u003e Once seated, the top of the sleeve is milled (decked) perfectly flush with the cylinder head surface. If it’s a two-stroke engine, the ports in the sleeve are manually blended to match the aluminum casting.\u003c\/span\u003e\n\u003c\/li\u003e\n\u003cli class=\"MsoNormal\"\u003e\n\u003cb\u003e\u003cspan\u003eFinal Hone:\u003c\/span\u003e\u003c\/b\u003e\u003cspan\u003e The sleeve is bored to just under the final size and then cross-hatch honed to the exact clearance required for the piston and ring set.\u003c\/span\u003e\n\u003c\/li\u003e\n\u003c\/ol\u003e\n\u003cdiv align=\"center\" class=\"MsoNormal\"\u003e\u003chr align=\"center\" width=\"100%\" size=\"2\"\u003e\u003c\/div\u003e\n\u003cp class=\"MsoNormal\"\u003e\u003cb\u003e\u003cspan\u003eWhy the Switch? The Advantages of Steel\u003c\/span\u003e\u003c\/b\u003e\u003c\/p\u003e\n\u003cp class=\"MsoNormal\"\u003e\u003cspan\u003eWhile Nikasil is prized for heat dissipation and low friction, steel sleeves offer practical, \"real-world\" benefits that many builders prefer for longevity and ease of maintenance.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp class=\"MsoNormal\"\u003e\u003cb\u003e\u003cspan\u003e1. Unlimited Serviceability (The \"One-and-Done\" Fix)\u003c\/span\u003e\u003c\/b\u003e\u003c\/p\u003e\n\u003cp class=\"MsoNormal\"\u003e\u003cspan\u003eNikasil is a coating only a few microns thick. If you \"cold seize\" the engine or ingest dirt, the coating is usually ruined, requiring the entire cylinder to be sent away for a costly and time-consuming stripping and replating process.\u003c\/span\u003e\u003c\/p\u003e\n\u003cul type=\"disc\"\u003e\n\u003cli class=\"MsoNormal\"\u003e\n\u003cb\u003e\u003cspan\u003eThe Steel Edge:\u003c\/span\u003e\u003c\/b\u003e\u003cspan\u003e If a sleeved cylinder gets scratched, you simply bore it to the next \"oversize\" ($0.25\\text{mm}$, $0.50\\text{mm}$, etc.) and install a larger piston. You can often do this 4 or 5 times before needing a new sleeve.\u003c\/span\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp class=\"MsoNormal\"\u003e\u003cb\u003e\u003cspan\u003e2. Cost-Effectiveness\u003c\/span\u003e\u003c\/b\u003e\u003c\/p\u003e\n\u003cp class=\"MsoNormal\"\u003e\u003cspan\u003eReplating Nikasil often costs significantly more than a simple bore and hone job at a local machine shop. By switching to steel, you eliminate the need for specialized chemical plating facilities in future rebuilds.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp class=\"MsoNormal\"\u003e\u003cb\u003e\u003cspan\u003e3. Durability Against Contaminants\u003c\/span\u003e\u003c\/b\u003e\u003c\/p\u003e\n\u003cp class=\"MsoNormal\"\u003e\u003cspan\u003eNikasil is notoriously sensitive to poor fuel quality (specifically high sulfur content) and can flake or \"peel\" under extreme conditions or improper storage. Steel is a much more forgiving material that handles varying fuel grades and environmental moisture with classic resilience.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp class=\"MsoNormal\"\u003e\u003cb\u003e\u003cspan\u003e4. Customization and Big Bore Potential\u003c\/span\u003e\u003c\/b\u003e\u003c\/p\u003e\n\u003cp class=\"MsoNormal\"\u003e\u003cspan\u003eWhen converting to a sleeve, builders often take the opportunity to \"over-bore\" the block beyond what the factory plating would allow. This is the easiest path to increasing displacement for more low-end grunt.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp class=\"MsoNormal\"\u003e\u003cb\u003e\u003cspan\u003eNote:\u003c\/span\u003e\u003c\/b\u003e\u003cspan\u003e While steel sleeves hold heat slightly longer than aluminum-backed Nikasil, for most recreational and woods-racing applications, the trade-off for \"bulletproof\" reliability and the ability to rebuild the engine in a single weekend is well worth it.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp class=\"MsoNormal\" style=\"text-align: center;\"\u003e\u003cspan style=\"color: rgb(255, 42, 0);\"\u003e\u003cb\u003e**RECOMMENDED TO PAIR WITH ANY CP 94mm PISTON **\u003c\/b\u003e\u003c\/span\u003e\u003c\/p\u003e","brand":"Zoom Zoom Parts","offers":[{"title":"Default Title","offer_id":49138974261471,"sku":"OEM STEEL SLEEVED 94mm TRX450R BLOCK ONLY","price":474.95,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0770\/0741\/files\/20260430_121602_ab41a0bf-1c42-4f1a-b99a-8fcb2ffefdce.jpg?v=1778606939"},{"product_id":"reconditioned-94mm-stock-bore-steel-sleeve-cylinder-block-for-2003-2014-suzuki-lt-z400-ltz400","title":"RECONDITIONED 90mm STOCK BORE STEEL SLEEVE CYLINDER BLOCK FOR 2003-2014 SUZUKI LT-Z400 LTZ400","description":"\u003cp class=\"MsoNormal\" align=\"center\"\u003e\u003cb\u003e\u003cspan\u003eRESLEEVED OEM SUZUKI BLOCK\u003c\/span\u003e\u003c\/b\u003e\u003cb\u003e\u003cspan\u003e\u003c\/span\u003e\u003c\/b\u003e\u003c\/p\u003e\n\u003cp class=\"MsoNormal\"\u003e\u003cspan\u003eThe transition from a high-performance Nikasil-plated cylinder to a traditional steel sleeve is a common \"reliability-first\" overhaul. It transforms a specialized, thin-film coating into a robust, serviceable component.\u003c\/span\u003e\u003c\/p\u003e\n\u003cdiv align=\"center\" class=\"MsoNormal\"\u003e\u003chr align=\"center\" width=\"100%\" size=\"2\"\u003e\u003c\/div\u003e\n\u003cp class=\"MsoNormal\"\u003e\u003cb\u003e\u003cspan\u003eThe Reconditioning Process: Precision Surgery\u003c\/span\u003e\u003c\/b\u003e\u003c\/p\u003e\n\u003cp class=\"MsoNormal\"\u003e\u003cspan\u003eConverting an OEM aluminum block to a steel sleeve is a multi-step machining operation that requires surgical accuracy:\u003c\/span\u003e\u003c\/p\u003e\n\u003col type=\"1\" start=\"1\"\u003e\n\u003cli class=\"MsoNormal\"\u003e\n\u003cb\u003e\u003cspan\u003eBoring the Host:\u003c\/span\u003e\u003c\/b\u003e\u003cspan\u003e The original cylinder is mounted on a boring bar or CNC mill. The Nikasil layer and a specific amount of the underlying aluminum are bored out to create a \"press-fit\" shoulder.\u003c\/span\u003e\n\u003c\/li\u003e\n\u003cli class=\"MsoNormal\"\u003e\n\u003cb\u003e\u003cspan\u003eThermal Interference Fit:\u003c\/span\u003e\u003c\/b\u003e\u003cspan\u003e To ensure the new sleeve never moves, the aluminum block is heated in an industrial oven to expand the bore, while the steel sleeve is often chilled in liquid nitrogen to shrink it. The sleeve is then pressed into the block.\u003c\/span\u003e\n\u003c\/li\u003e\n\u003cli class=\"MsoNormal\"\u003e\n\u003cb\u003e\u003cspan\u003eDecking and Porting:\u003c\/span\u003e\u003c\/b\u003e\u003cspan\u003e Once seated, the top of the sleeve is milled (decked) perfectly flush with the cylinder head surface. If it’s a two-stroke engine, the ports in the sleeve are manually blended to match the aluminum casting.\u003c\/span\u003e\n\u003c\/li\u003e\n\u003cli class=\"MsoNormal\"\u003e\n\u003cb\u003e\u003cspan\u003eFinal Hone:\u003c\/span\u003e\u003c\/b\u003e\u003cspan\u003e The sleeve is bored to just under the final size and then cross-hatch honed to the exact clearance required for the piston and ring set.\u003c\/span\u003e\n\u003c\/li\u003e\n\u003c\/ol\u003e\n\u003cdiv align=\"center\" class=\"MsoNormal\"\u003e\u003chr align=\"center\" width=\"100%\" size=\"2\"\u003e\u003c\/div\u003e\n\u003cp class=\"MsoNormal\"\u003e\u003cb\u003e\u003cspan\u003eWhy the Switch? The Advantages of Steel\u003c\/span\u003e\u003c\/b\u003e\u003c\/p\u003e\n\u003cp class=\"MsoNormal\"\u003e\u003cspan\u003eWhile Nikasil is prized for heat dissipation and low friction, steel sleeves offer practical, \"real-world\" benefits that many builders prefer for longevity and ease of maintenance.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp class=\"MsoNormal\"\u003e\u003cb\u003e\u003cspan\u003e1. Unlimited Serviceability (The \"One-and-Done\" Fix)\u003c\/span\u003e\u003c\/b\u003e\u003c\/p\u003e\n\u003cp class=\"MsoNormal\"\u003e\u003cspan\u003eNikasil is a coating only a few microns thick. If you \"cold seize\" the engine or ingest dirt, the coating is usually ruined, requiring the entire cylinder to be sent away for a costly and time-consuming stripping and replating process.\u003c\/span\u003e\u003c\/p\u003e\n\u003cul type=\"disc\"\u003e\n\u003cli class=\"MsoNormal\"\u003e\n\u003cb\u003e\u003cspan\u003eThe Steel Edge:\u003c\/span\u003e\u003c\/b\u003e\u003cspan\u003e If a sleeved cylinder gets scratched, you simply bore it to the next \"oversize\" ($0.25\\text{mm}$, $0.50\\text{mm}$, etc.) and install a larger piston. You can often do this 4 or 5 times before needing a new sleeve.\u003c\/span\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp class=\"MsoNormal\"\u003e\u003cb\u003e\u003cspan\u003e2. Cost-Effectiveness\u003c\/span\u003e\u003c\/b\u003e\u003c\/p\u003e\n\u003cp class=\"MsoNormal\"\u003e\u003cspan\u003eReplating Nikasil often costs significantly more than a simple bore and hone job at a local machine shop. By switching to steel, you eliminate the need for specialized chemical plating facilities in future rebuilds.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp class=\"MsoNormal\"\u003e\u003cb\u003e\u003cspan\u003e3. Durability Against Contaminants\u003c\/span\u003e\u003c\/b\u003e\u003c\/p\u003e\n\u003cp class=\"MsoNormal\"\u003e\u003cspan\u003eNikasil is notoriously sensitive to poor fuel quality (specifically high sulfur content) and can flake or \"peel\" under extreme conditions or improper storage. Steel is a much more forgiving material that handles varying fuel grades and environmental moisture with classic resilience.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp class=\"MsoNormal\"\u003e\u003cb\u003e\u003cspan\u003e4. Customization and Big Bore Potential\u003c\/span\u003e\u003c\/b\u003e\u003c\/p\u003e\n\u003cp class=\"MsoNormal\"\u003e\u003cspan\u003eWhen converting to a sleeve, builders often take the opportunity to \"over-bore\" the block beyond what the factory plating would allow. This is the easiest path to increasing displacement for more low-end grunt.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp class=\"MsoNormal\"\u003e\u003cb\u003e\u003cspan\u003eNote:\u003c\/span\u003e\u003c\/b\u003e\u003cspan\u003e While steel sleeves hold heat slightly longer than aluminum-backed Nikasil, for most recreational and woods-racing applications, the trade-off for \"bulletproof\" reliability and the ability to rebuild the engine in a single weekend is well worth it.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp class=\"MsoNormal\" style=\"text-align: center;\"\u003e\u003cspan style=\"color: rgb(255, 42, 0);\"\u003e\u003cb\u003e**RECOMMENDED TO PAIR WITH ANY CP 90mm PISTON **\u003c\/b\u003e\u003c\/span\u003e\u003c\/p\u003e","brand":"Zoom Zoom Parts","offers":[{"title":"Default Title","offer_id":49173769224415,"sku":"OEM LTZ400 DUCTILE SLEEVE 90mm (B) BLOCK ONLY","price":424.95,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0770\/0741\/files\/20260512_141626_c7684f5f-d754-417e-bdc0-0cfd1041eee2.jpg?v=1778684656"},{"product_id":"reconditioned-90mm-stock-bore-steel-sleeve-cylinder-block-for-2003-2006-kawasaki-kfx400","title":"RECONDITIONED 90mm STOCK BORE STEEL SLEEVE CYLINDER BLOCK FOR 2003-2006 KAWASAKI KFX400","description":"\u003cp class=\"MsoNormal\" align=\"center\"\u003e\u003cb\u003e\u003cspan\u003eRESLEEVED OEM KAWASAKI BLOCK\u003c\/span\u003e\u003c\/b\u003e\u003cb\u003e\u003cspan\u003e\u003c\/span\u003e\u003c\/b\u003e\u003c\/p\u003e\n\u003cp class=\"MsoNormal\"\u003e\u003cspan\u003eThe transition from a high-performance Nikasil-plated cylinder to a traditional steel sleeve is a common \"reliability-first\" overhaul. It transforms a specialized, thin-film coating into a robust, serviceable component.\u003c\/span\u003e\u003c\/p\u003e\n\u003cdiv align=\"center\" class=\"MsoNormal\"\u003e\u003chr align=\"center\" width=\"100%\" size=\"2\"\u003e\u003c\/div\u003e\n\u003cp class=\"MsoNormal\"\u003e\u003cb\u003e\u003cspan\u003eThe Reconditioning Process: Precision Surgery\u003c\/span\u003e\u003c\/b\u003e\u003c\/p\u003e\n\u003cp class=\"MsoNormal\"\u003e\u003cspan\u003eConverting an OEM aluminum block to a steel sleeve is a multi-step machining operation that requires surgical accuracy:\u003c\/span\u003e\u003c\/p\u003e\n\u003col type=\"1\" start=\"1\"\u003e\n\u003cli class=\"MsoNormal\"\u003e\n\u003cb\u003e\u003cspan\u003eBoring the Host:\u003c\/span\u003e\u003c\/b\u003e\u003cspan\u003e The original cylinder is mounted on a boring bar or CNC mill. The Nikasil layer and a specific amount of the underlying aluminum are bored out to create a \"press-fit\" shoulder.\u003c\/span\u003e\n\u003c\/li\u003e\n\u003cli class=\"MsoNormal\"\u003e\n\u003cb\u003e\u003cspan\u003eThermal Interference Fit:\u003c\/span\u003e\u003c\/b\u003e\u003cspan\u003e To ensure the new sleeve never moves, the aluminum block is heated in an industrial oven to expand the bore, while the steel sleeve is often chilled in liquid nitrogen to shrink it. The sleeve is then pressed into the block.\u003c\/span\u003e\n\u003c\/li\u003e\n\u003cli class=\"MsoNormal\"\u003e\n\u003cb\u003e\u003cspan\u003eDecking and Porting:\u003c\/span\u003e\u003c\/b\u003e\u003cspan\u003e Once seated, the top of the sleeve is milled (decked) perfectly flush with the cylinder head surface. If it’s a two-stroke engine, the ports in the sleeve are manually blended to match the aluminum casting.\u003c\/span\u003e\n\u003c\/li\u003e\n\u003cli class=\"MsoNormal\"\u003e\n\u003cb\u003e\u003cspan\u003eFinal Hone:\u003c\/span\u003e\u003c\/b\u003e\u003cspan\u003e The sleeve is bored to just under the final size and then cross-hatch honed to the exact clearance required for the piston and ring set.\u003c\/span\u003e\n\u003c\/li\u003e\n\u003c\/ol\u003e\n\u003cdiv align=\"center\" class=\"MsoNormal\"\u003e\u003chr align=\"center\" width=\"100%\" size=\"2\"\u003e\u003c\/div\u003e\n\u003cp class=\"MsoNormal\"\u003e\u003cb\u003e\u003cspan\u003eWhy the Switch? The Advantages of Steel\u003c\/span\u003e\u003c\/b\u003e\u003c\/p\u003e\n\u003cp class=\"MsoNormal\"\u003e\u003cspan\u003eWhile Nikasil is prized for heat dissipation and low friction, steel sleeves offer practical, \"real-world\" benefits that many builders prefer for longevity and ease of maintenance.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp class=\"MsoNormal\"\u003e\u003cb\u003e\u003cspan\u003e1. Unlimited Serviceability (The \"One-and-Done\" Fix)\u003c\/span\u003e\u003c\/b\u003e\u003c\/p\u003e\n\u003cp class=\"MsoNormal\"\u003e\u003cspan\u003eNikasil is a coating only a few microns thick. If you \"cold seize\" the engine or ingest dirt, the coating is usually ruined, requiring the entire cylinder to be sent away for a costly and time-consuming stripping and replating process.\u003c\/span\u003e\u003c\/p\u003e\n\u003cul type=\"disc\"\u003e\n\u003cli class=\"MsoNormal\"\u003e\n\u003cb\u003e\u003cspan\u003eThe Steel Edge:\u003c\/span\u003e\u003c\/b\u003e\u003cspan\u003e If a sleeved cylinder gets scratched, you simply bore it to the next \"oversize\" ($0.25\\text{mm}$, $0.50\\text{mm}$, etc.) and install a larger piston. You can often do this 4 or 5 times before needing a new sleeve.\u003c\/span\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp class=\"MsoNormal\"\u003e\u003cb\u003e\u003cspan\u003e2. Cost-Effectiveness\u003c\/span\u003e\u003c\/b\u003e\u003c\/p\u003e\n\u003cp class=\"MsoNormal\"\u003e\u003cspan\u003eReplating Nikasil often costs significantly more than a simple bore and hone job at a local machine shop. By switching to steel, you eliminate the need for specialized chemical plating facilities in future rebuilds.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp class=\"MsoNormal\"\u003e\u003cb\u003e\u003cspan\u003e3. Durability Against Contaminants\u003c\/span\u003e\u003c\/b\u003e\u003c\/p\u003e\n\u003cp class=\"MsoNormal\"\u003e\u003cspan\u003eNikasil is notoriously sensitive to poor fuel quality (specifically high sulfur content) and can flake or \"peel\" under extreme conditions or improper storage. Steel is a much more forgiving material that handles varying fuel grades and environmental moisture with classic resilience.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp class=\"MsoNormal\"\u003e\u003cb\u003e\u003cspan\u003e4. Customization and Big Bore Potential\u003c\/span\u003e\u003c\/b\u003e\u003c\/p\u003e\n\u003cp class=\"MsoNormal\"\u003e\u003cspan\u003eWhen converting to a sleeve, builders often take the opportunity to \"over-bore\" the block beyond what the factory plating would allow. This is the easiest path to increasing displacement for more low-end grunt.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp class=\"MsoNormal\"\u003e\u003cb\u003e\u003cspan\u003eNote:\u003c\/span\u003e\u003c\/b\u003e\u003cspan\u003e While steel sleeves hold heat slightly longer than aluminum-backed Nikasil, for most recreational and woods-racing applications, the trade-off for \"bulletproof\" reliability and the ability to rebuild the engine in a single weekend is well worth it.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp class=\"MsoNormal\" style=\"text-align: center;\"\u003e\u003cspan style=\"color: rgb(255, 42, 0);\"\u003e\u003cb\u003e**RECOMMENDED TO PAIR WITH ANY CP 90mm PISTON **\u003c\/b\u003e\u003c\/span\u003e\u003c\/p\u003e","brand":"Zoom Zoom Parts","offers":[{"title":"Default Title","offer_id":49173773484255,"sku":"OEM KFX400 DUCTILE STEEL SLEEVE CYLINDER 90mm KIT (A) BLOCK ONLY","price":424.95,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0770\/0741\/files\/20260512_150140_385817a0-b681-4fd3-a141-5b30a1d14d1f.jpg?v=1778685040"},{"product_id":"reconditioned-2s200-y-1-95mm-stock-bore-steel-sleeve-cylinder-block-for-2009-2025-yamaha-yfz450r","title":"RECONDITIONED 2S200 Y-1 95mm STOCK BORE STEEL SLEEVE CYLINDER BLOCK FOR 2009-2025 YAMAHA YFZ450R","description":"\u003cp class=\"MsoNormal\" align=\"center\"\u003e\u003cb\u003e\u003cspan\u003eRESLEEVED OEM 2S200 Y-1 YAMAHA BLOCK\u003c\/span\u003e\u003c\/b\u003e\u003cb\u003e\u003cspan\u003e\u003c\/span\u003e\u003c\/b\u003e\u003c\/p\u003e\n\u003cp class=\"MsoNormal\"\u003e\u003cspan\u003eThe transition from a high-performance Nikasil-plated cylinder to a traditional steel sleeve is a common \"reliability-first\" overhaul. It transforms a specialized, thin-film coating into a robust, serviceable component.\u003c\/span\u003e\u003c\/p\u003e\n\u003cdiv align=\"center\" class=\"MsoNormal\"\u003e\u003chr align=\"center\" width=\"100%\" size=\"2\"\u003e\u003c\/div\u003e\n\u003cp class=\"MsoNormal\"\u003e\u003cb\u003e\u003cspan\u003eThe Reconditioning Process: Precision Surgery\u003c\/span\u003e\u003c\/b\u003e\u003c\/p\u003e\n\u003cp class=\"MsoNormal\"\u003e\u003cspan\u003eConverting an OEM aluminum block to a steel sleeve is a multi-step machining operation that requires surgical accuracy:\u003c\/span\u003e\u003c\/p\u003e\n\u003col type=\"1\" start=\"1\"\u003e\n\u003cli class=\"MsoNormal\"\u003e\n\u003cb\u003e\u003cspan\u003eBoring the Host:\u003c\/span\u003e\u003c\/b\u003e\u003cspan\u003e The original cylinder is mounted on a boring bar or CNC mill. The Nikasil layer and a specific amount of the underlying aluminum are bored out to create a \"press-fit\" shoulder.\u003c\/span\u003e\n\u003c\/li\u003e\n\u003cli class=\"MsoNormal\"\u003e\n\u003cb\u003e\u003cspan\u003eThermal Interference Fit:\u003c\/span\u003e\u003c\/b\u003e\u003cspan\u003e To ensure the new sleeve never moves, the aluminum block is heated in an industrial oven to expand the bore, while the steel sleeve is often chilled in liquid nitrogen to shrink it. The sleeve is then pressed into the block.\u003c\/span\u003e\n\u003c\/li\u003e\n\u003cli class=\"MsoNormal\"\u003e\n\u003cb\u003e\u003cspan\u003eDecking and Porting:\u003c\/span\u003e\u003c\/b\u003e\u003cspan\u003e Once seated, the top of the sleeve is milled (decked) perfectly flush with the cylinder head surface. If it’s a two-stroke engine, the ports in the sleeve are manually blended to match the aluminum casting.\u003c\/span\u003e\n\u003c\/li\u003e\n\u003cli class=\"MsoNormal\"\u003e\n\u003cb\u003e\u003cspan\u003eFinal Hone:\u003c\/span\u003e\u003c\/b\u003e\u003cspan\u003e The sleeve is bored to just under the final size and then cross-hatch honed to the exact clearance required for the piston and ring set.\u003c\/span\u003e\n\u003c\/li\u003e\n\u003c\/ol\u003e\n\u003cdiv align=\"center\" class=\"MsoNormal\"\u003e\u003chr align=\"center\" width=\"100%\" size=\"2\"\u003e\u003c\/div\u003e\n\u003cp class=\"MsoNormal\"\u003e\u003cb\u003e\u003cspan\u003eWhy the Switch? The Advantages of Steel\u003c\/span\u003e\u003c\/b\u003e\u003c\/p\u003e\n\u003cp class=\"MsoNormal\"\u003e\u003cspan\u003eWhile Nikasil is prized for heat dissipation and low friction, steel sleeves offer practical, \"real-world\" benefits that many builders prefer for longevity and ease of maintenance.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp class=\"MsoNormal\"\u003e\u003cb\u003e\u003cspan\u003e1. Unlimited Serviceability (The \"One-and-Done\" Fix)\u003c\/span\u003e\u003c\/b\u003e\u003c\/p\u003e\n\u003cp class=\"MsoNormal\"\u003e\u003cspan\u003eNikasil is a coating only a few microns thick. If you \"cold seize\" the engine or ingest dirt, the coating is usually ruined, requiring the entire cylinder to be sent away for a costly and time-consuming stripping and replating process.\u003c\/span\u003e\u003c\/p\u003e\n\u003cul type=\"disc\"\u003e\n\u003cli class=\"MsoNormal\"\u003e\n\u003cb\u003e\u003cspan\u003eThe Steel Edge:\u003c\/span\u003e\u003c\/b\u003e\u003cspan\u003e If a sleeved cylinder gets scratched, you simply bore it to the next \"oversize\" ($0.25\\text{mm}$, $0.50\\text{mm}$, etc.) and install a larger piston. You can often do this 4 or 5 times before needing a new sleeve.\u003c\/span\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp class=\"MsoNormal\"\u003e\u003cb\u003e\u003cspan\u003e2. Cost-Effectiveness\u003c\/span\u003e\u003c\/b\u003e\u003c\/p\u003e\n\u003cp class=\"MsoNormal\"\u003e\u003cspan\u003eReplating Nikasil often costs significantly more than a simple bore and hone job at a local machine shop. By switching to steel, you eliminate the need for specialized chemical plating facilities in future rebuilds.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp class=\"MsoNormal\"\u003e\u003cb\u003e\u003cspan\u003e3. Durability Against Contaminants\u003c\/span\u003e\u003c\/b\u003e\u003c\/p\u003e\n\u003cp class=\"MsoNormal\"\u003e\u003cspan\u003eNikasil is notoriously sensitive to poor fuel quality (specifically high sulfur content) and can flake or \"peel\" under extreme conditions or improper storage. Steel is a much more forgiving material that handles varying fuel grades and environmental moisture with classic resilience.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp class=\"MsoNormal\"\u003e\u003cb\u003e\u003cspan\u003e4. Customization and Big Bore Potential\u003c\/span\u003e\u003c\/b\u003e\u003c\/p\u003e\n\u003cp class=\"MsoNormal\"\u003e\u003cspan\u003eWhen converting to a sleeve, builders often take the opportunity to \"over-bore\" the block beyond what the factory plating would allow. This is the easiest path to increasing displacement for more low-end grunt.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp class=\"MsoNormal\"\u003e\u003cb\u003e\u003cspan\u003eNote:\u003c\/span\u003e\u003c\/b\u003e\u003cspan\u003e While steel sleeves hold heat slightly longer than aluminum-backed Nikasil, for most recreational and woods-racing applications, the trade-off for \"bulletproof\" reliability and the ability to rebuild the engine in a single weekend is well worth it.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp class=\"MsoNormal\" style=\"text-align: center;\"\u003e\u003cspan style=\"color: rgb(255, 42, 0);\"\u003e\u003cb\u003e**RECOMMENDED TO PAIR WITH ANY CP 95mm PISTON **\u003c\/b\u003e\u003c\/span\u003e\u003c\/p\u003e","brand":"Zoom Zoom Parts","offers":[{"title":"Default Title","offer_id":49176109318367,"sku":"OEM YFZ450R 2S200 Y-1 SLEEVED BLOCK ONLY A","price":499.95,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0770\/0741\/files\/20260514_120957_b5662427-9122-4c99-abe1-23cb1e4ddb8d.jpg?v=1778780300"},{"product_id":"reconditioned-2s200-y-2-95mm-stock-bore-steel-sleeve-cylinder-block-for-2009-2025-yamaha-yfz450r","title":"RECONDITIONED 2S200 Y-2 95mm STOCK BORE STEEL SLEEVE CYLINDER BLOCK FOR 2009-2025 YAMAHA YFZ450R","description":"\u003cp class=\"MsoNormal\" align=\"center\"\u003e\u003cb\u003e\u003cspan\u003eRESLEEVED OEM 2S200 Y-2 YAMAHA BLOCK\u003c\/span\u003e\u003c\/b\u003e\u003cb\u003e\u003cspan\u003e\u003c\/span\u003e\u003c\/b\u003e\u003c\/p\u003e\n\u003cp class=\"MsoNormal\"\u003e\u003cspan\u003eThe transition from a high-performance Nikasil-plated cylinder to a traditional steel sleeve is a common \"reliability-first\" overhaul. It transforms a specialized, thin-film coating into a robust, serviceable component.\u003c\/span\u003e\u003c\/p\u003e\n\u003cdiv align=\"center\" class=\"MsoNormal\"\u003e\u003chr align=\"center\" width=\"100%\" size=\"2\"\u003e\u003c\/div\u003e\n\u003cp class=\"MsoNormal\"\u003e\u003cb\u003e\u003cspan\u003eThe Reconditioning Process: Precision Surgery\u003c\/span\u003e\u003c\/b\u003e\u003c\/p\u003e\n\u003cp class=\"MsoNormal\"\u003e\u003cspan\u003eConverting an OEM aluminum block to a steel sleeve is a multi-step machining operation that requires surgical accuracy:\u003c\/span\u003e\u003c\/p\u003e\n\u003col type=\"1\" start=\"1\"\u003e\n\u003cli class=\"MsoNormal\"\u003e\n\u003cb\u003e\u003cspan\u003eBoring the Host:\u003c\/span\u003e\u003c\/b\u003e\u003cspan\u003e The original cylinder is mounted on a boring bar or CNC mill. The Nikasil layer and a specific amount of the underlying aluminum are bored out to create a \"press-fit\" shoulder.\u003c\/span\u003e\n\u003c\/li\u003e\n\u003cli class=\"MsoNormal\"\u003e\n\u003cb\u003e\u003cspan\u003eThermal Interference Fit:\u003c\/span\u003e\u003c\/b\u003e\u003cspan\u003e To ensure the new sleeve never moves, the aluminum block is heated in an industrial oven to expand the bore, while the steel sleeve is often chilled in liquid nitrogen to shrink it. The sleeve is then pressed into the block.\u003c\/span\u003e\n\u003c\/li\u003e\n\u003cli class=\"MsoNormal\"\u003e\n\u003cb\u003e\u003cspan\u003eDecking and Porting:\u003c\/span\u003e\u003c\/b\u003e\u003cspan\u003e Once seated, the top of the sleeve is milled (decked) perfectly flush with the cylinder head surface. If it’s a two-stroke engine, the ports in the sleeve are manually blended to match the aluminum casting.\u003c\/span\u003e\n\u003c\/li\u003e\n\u003cli class=\"MsoNormal\"\u003e\n\u003cb\u003e\u003cspan\u003eFinal Hone:\u003c\/span\u003e\u003c\/b\u003e\u003cspan\u003e The sleeve is bored to just under the final size and then cross-hatch honed to the exact clearance required for the piston and ring set.\u003c\/span\u003e\n\u003c\/li\u003e\n\u003c\/ol\u003e\n\u003cdiv align=\"center\" class=\"MsoNormal\"\u003e\u003chr align=\"center\" width=\"100%\" size=\"2\"\u003e\u003c\/div\u003e\n\u003cp class=\"MsoNormal\"\u003e\u003cb\u003e\u003cspan\u003eWhy the Switch? The Advantages of Steel\u003c\/span\u003e\u003c\/b\u003e\u003c\/p\u003e\n\u003cp class=\"MsoNormal\"\u003e\u003cspan\u003eWhile Nikasil is prized for heat dissipation and low friction, steel sleeves offer practical, \"real-world\" benefits that many builders prefer for longevity and ease of maintenance.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp class=\"MsoNormal\"\u003e\u003cb\u003e\u003cspan\u003e1. Unlimited Serviceability (The \"One-and-Done\" Fix)\u003c\/span\u003e\u003c\/b\u003e\u003c\/p\u003e\n\u003cp class=\"MsoNormal\"\u003e\u003cspan\u003eNikasil is a coating only a few microns thick. If you \"cold seize\" the engine or ingest dirt, the coating is usually ruined, requiring the entire cylinder to be sent away for a costly and time-consuming stripping and replating process.\u003c\/span\u003e\u003c\/p\u003e\n\u003cul type=\"disc\"\u003e\n\u003cli class=\"MsoNormal\"\u003e\n\u003cb\u003e\u003cspan\u003eThe Steel Edge:\u003c\/span\u003e\u003c\/b\u003e\u003cspan\u003e If a sleeved cylinder gets scratched, you simply bore it to the next \"oversize\" ($0.25\\text{mm}$, $0.50\\text{mm}$, etc.) and install a larger piston. You can often do this 4 or 5 times before needing a new sleeve.\u003c\/span\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp class=\"MsoNormal\"\u003e\u003cb\u003e\u003cspan\u003e2. Cost-Effectiveness\u003c\/span\u003e\u003c\/b\u003e\u003c\/p\u003e\n\u003cp class=\"MsoNormal\"\u003e\u003cspan\u003eReplating Nikasil often costs significantly more than a simple bore and hone job at a local machine shop. By switching to steel, you eliminate the need for specialized chemical plating facilities in future rebuilds.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp class=\"MsoNormal\"\u003e\u003cb\u003e\u003cspan\u003e3. Durability Against Contaminants\u003c\/span\u003e\u003c\/b\u003e\u003c\/p\u003e\n\u003cp class=\"MsoNormal\"\u003e\u003cspan\u003eNikasil is notoriously sensitive to poor fuel quality (specifically high sulfur content) and can flake or \"peel\" under extreme conditions or improper storage. Steel is a much more forgiving material that handles varying fuel grades and environmental moisture with classic resilience.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp class=\"MsoNormal\"\u003e\u003cb\u003e\u003cspan\u003e4. Customization and Big Bore Potential\u003c\/span\u003e\u003c\/b\u003e\u003c\/p\u003e\n\u003cp class=\"MsoNormal\"\u003e\u003cspan\u003eWhen converting to a sleeve, builders often take the opportunity to \"over-bore\" the block beyond what the factory plating would allow. This is the easiest path to increasing displacement for more low-end grunt.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp class=\"MsoNormal\"\u003e\u003cb\u003e\u003cspan\u003eNote:\u003c\/span\u003e\u003c\/b\u003e\u003cspan\u003e While steel sleeves hold heat slightly longer than aluminum-backed Nikasil, for most recreational and woods-racing applications, the trade-off for \"bulletproof\" reliability and the ability to rebuild the engine in a single weekend is well worth it.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp class=\"MsoNormal\" style=\"text-align: center;\"\u003e\u003cspan style=\"color: rgb(255, 42, 0);\"\u003e\u003cb\u003e**RECOMMENDED TO PAIR WITH ANY CP 95mm PISTON **\u003c\/b\u003e\u003c\/span\u003e\u003c\/p\u003e","brand":"Zoom Zoom Parts","offers":[{"title":"Default Title","offer_id":49176113152223,"sku":"OEM YFZ450R 2S200 Y-2 SLEEVED BLOCK ONLY B","price":499.95,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0770\/0741\/files\/20260514_121241_620ebc0e-b0b7-4879-b0a1-2df01c7b6b86.jpg?v=1778780730"}],"url":"https:\/\/zoomzoomparts.com\/collections\/refurbished-oem-steel-sleeved-blocks.oembed","provider":"Zoom Zoom Parts","version":"1.0","type":"link"}