{"product_id":"ncy-cylinder-head-2-valve-big-valve-61mm-genuine-gy6-1100-1254","title":"NCY Big Valve High-Flow Cylinder Head - 61mm GY6 (171cc)","description":"\u003cp\u003eMaximize your motor's torque and top-end breathing capacity with the premium \u003cstrong\u003eNCY Big Valve High-Flow Cylinder Head\u003c\/strong\u003e. Engineered specifically to complement large-displacement performance upgrades, this 61mm cylinder head features optimized porting and oversized valves that allow your engine to move air in and out of the combustion chamber far more efficiently. The result is an immediate boost in throttle response, cleaner acceleration, and smoother operation across your entire power band.\u003c\/p\u003e\u003cp\u003ePlease note: This item is sold without any additional parts.  It is the cylinder head body by itself. \u003c\/p\u003e\u003ch3\u003eAdvanced Performance Features\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eOversized Valve Setup:\u003c\/strong\u003e Equipped with large 27.8mm intake and 22.9mm exhaust valves to drastically decrease intake restriction and optimize cylinder head breathing.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eHigh-Flow Porting Matrix:\u003c\/strong\u003e Cast and precision-finished in Taiwan with smooth internal runners that eliminate factory restrictions and fuel puddling.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eThermal Management Layout:\u003c\/strong\u003e Constructed from a premium-grade aluminum alloy with wide cooling fins to quickly shed heat under extreme, high-bore engine loads.\u003c\/li\u003e\n\u003c\/ul\u003e\u003chr\u003e\u003ch3\u003eVehicle \u0026amp; Engine Fitment\u003c\/h3\u003e\u003cp\u003eThis high-performance big valve head is tailored as a premium bolt-on upgrade for standard (B-Case) air-cooled GY6 4-stroke platforms. Built strictly for \u003ca href=\"\/products\/ncy-cylinder-kit-aluminum-61mm-171cc-genuinegy6-1100-1288\"\u003e61mm \/ 171cc cylinder kits (SKU 1100-1288)\u003c\/a\u003e.\u003c\/p\u003e\u003cp\u003eOEM replacement valves are Sku: \u003ca href=\"https:\/\/www.scooterworks.com\/products\/ncy-racing-valves-gy6-1100-1257?variant=46756522066200\"\u003e1100-1257\u003c\/a\u003e NCY High-RPM Racing Valve Set - 28\/23mm for GY6\u003c\/p\u003e\u003cdiv class=\"product-sku\" id=\"sku-template--20517470273816__main-product\"\u003e\u003cbr\u003e\u003c\/div\u003e\u003ctable\u003e\n\u003cthead\u003e\u003ctr\u003e\n\u003cth style=\"text-align: left;\"\u003eVehicle Manufacturer \/ Class\u003c\/th\u003e\n\u003cth style=\"text-align: left;\"\u003eSpecific Eligible Model \u0026amp; Engine Lines\u003c\/th\u003e\n\u003c\/tr\u003e\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eGenuine Scooter Co.\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eBuddy 125, Buddy 150, Buddy 170i, Hooligan 170i, Blur 150\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eGo-Karts \/ Buggies\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eHammerhead 150, Trailmaster 150 (All Variants), Yerf-Dog, Carter Talon\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eChinese GY6 Brands\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eTaoTao, Wolf, Ice Bear, Bintelli, Peace Sports, ZNEN, SSR, and Kymco\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eApplicable Engine Codes\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e157QMJ, 1P57QMJ, 152QMI, 161QMK, BN157QMJ, BN161QMK-A\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\u003cp\u003e\u003cstrong\u003eTUNING REQUIREMENT:\u003c\/strong\u003e Upgrading to a high-flow, big-valve setup demands significantly more fuel. To prevent a dangerous lean condition, you must upjet your carburetor (typically a #125 or #130 main jet depending on elevation).\u003c\/p\u003e\u003chr\u003e\u003ch3\u003eTechnical Specifications\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eIntake Valve Diameter:\u003c\/strong\u003e 27.8 mm\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eExhaust Valve Diameter:\u003c\/strong\u003e 22.9 mm\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eExhaust Thread:\u003c\/strong\u003e Standard 8mm diameter\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eTarget Cylinder Bore:\u003c\/strong\u003e 61mm (Up to 171cc)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eManufacturing Origin:\u003c\/strong\u003e Taiwan (ISO 9001 Certified)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSKU:\u003c\/strong\u003e 1100-1254\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003eVisit our \u003ca href=\"https:\/\/www.scooterworks.com\/collections\/ncy-performance-parts\"\u003eNCY Performance Parts\u003c\/a\u003e page to shop all performance upgrades available for your vehicle.\u003c\/p\u003e\u003chr\u003e\u003cblockquote\u003e\u003cp\u003e\u003cstrong\u003eMechanic's Installation Tip:\u003c\/strong\u003e Big bore and high-flow head upgrades naturally increase internal crankcase pressures. We highly recommend pairing this build with a \u003ca href=\"https:\/\/www.scooterworks.com\/collections\/ncy-performance-parts\"\u003eDecompression Tube Assembly\u003c\/a\u003e in place of your oil dipstick to vent excess pressure safely. Always double-check your valve clearance settings using a feeler gauge after torquing down the head bolts to prevent mechanical contact on your initial startup.\u003c\/p\u003e\u003c\/blockquote\u003e\u003chr\u003e\u003ch3\u003eAbout NCY\u003c\/h3\u003e\u003cp\u003eNCY is the aftermarket performance parts leader for the most popular scooter brands, including Honda, Yamaha, Genuine, Vespa, SYM, Lance, KYMCO, and GY6\/QMB powered scooters. Made in Taiwan with strict quality standards since 1997, NCY is ISO 9001 certified.\u003c\/p\u003e\u003cp style=\"font-size: 0.85em; color: #666;\"\u003e\u003cstrong\u003eSKU:\u003c\/strong\u003e 1100-1254  |  \u003cstrong\u003eVendor:\u003c\/strong\u003e NCY  |  \u003cstrong\u003eCategory:\u003c\/strong\u003e Cylinder Heads in Motor Vehicle Engine Parts\u003c\/p\u003e\u003cp style=\"color: #983d3c;\"\u003e\u003cstrong\u003eThis product is not intended for use on public roads or land.\u003c\/strong\u003e\u003c\/p\u003e\u003cp style=\"color: #983d3c;\"\u003e\u003cstrong\u003eNot legal for use in California on pollution-controlled vehicles. Check local laws before installation.\u003c\/strong\u003e\u003c\/p\u003e\u003chr\u003e\u003cp\u003e\u003ca href=\"https:\/\/www.P65Warnings.ca.gov\" target=\"_blank\"\u003eCalifornia Prop 65 Warning: www.P65Warnings.ca.gov\u003c\/a\u003e\u003c\/p\u003e","brand":"NCY","offers":[{"title":"Default Title","offer_id":48111860023483,"sku":"1100-1254","price":139.0,"currency_code":"USD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0719\/1340\/6651\/files\/02.png?v=1784297060","url":"https:\/\/thriftyscooters.com\/products\/ncy-cylinder-head-2-valve-big-valve-61mm-genuine-gy6-1100-1254","provider":"Thrifty Scooters","version":"1.0","type":"link"}