{"product_id":"yamaha-qt50-60cc-big-bore-cylinder-head-piston-kit-44mm-1979-1987","title":"Yamaha QT50 60cc Big Bore Cylinder Head Piston Kit 44mm 1979-1987","description":"\u003ch2\u003eYamaha QT50 60cc Big Bore Cylinder Head \u0026amp; Piston Kit 1979–1987 – 44mm\u003c\/h2\u003e\n\u003cp\u003eNew aftermarket 44 mm big-bore cylinder, head and piston kit for Yamaha QT50 applications. Matching aftermarket catalogues list this 44 mm \/ nominal 60 cc top-end conversion for QT50 1979–1987.\u003c\/p\u003e\n\n\u003ch3\u003eKey Details\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eProduct:\u003c\/strong\u003e Cylinder, head and piston big-bore top-end kit\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eNominal capacity:\u003c\/strong\u003e 60 cc\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eBore:\u003c\/strong\u003e 44 mm\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eStandard bore replaced:\u003c\/strong\u003e 40 mm\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eEngine type:\u003c\/strong\u003e 2-stroke\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCondition:\u003c\/strong\u003e New\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eType:\u003c\/strong\u003e Aftermarket big-bore conversion \/ replacement kit\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eVehicle Compatibility\u003c\/h3\u003e\n\u003ctable\u003e\n\u003cthead\u003e\u003ctr\u003e\n\u003cth\u003eMake\u003c\/th\u003e\n\u003cth\u003eModel\u003c\/th\u003e\n\u003cth\u003eYears\u003c\/th\u003e\n\u003cth\u003eApplication\u003c\/th\u003e\n\u003c\/tr\u003e\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eYamaha\u003c\/td\u003e\n\u003ctd\u003eQT50\u003c\/td\u003e\n\u003ctd\u003e1979–1987\u003c\/td\u003e\n\u003ctd\u003e44 mm \/ nominal 60 cc big-bore top-end conversion\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\n\n\u003ch3\u003eYamaha \/ Application Reference Numbers\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003ePW50 standard cylinder:\u003c\/strong\u003e 4J2-11311-01 \/ 4J21131101\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eEarlier PW50 cylinder reference:\u003c\/strong\u003e 4J2-11311-00 \/ 4J21131100\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePW50 cylinder head:\u003c\/strong\u003e 4J2-11111-01 \/ 4J21111101\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eEarlier cylinder-head reference:\u003c\/strong\u003e 4J2-11111-00 \/ 4J21111100\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCylinder-head gasket:\u003c\/strong\u003e 517-11181-01 \/ 5171118101\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCylinder base gasket:\u003c\/strong\u003e 3PT-11351-00 \/ 3PT1135100\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCylinder studs:\u003c\/strong\u003e 90116-06418 \/ 9011606418\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFlange nuts:\u003c\/strong\u003e 95707-06500 \/ 9570706500\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003eThese are Yamaha application\/reference numbers for the standard components that this big-bore conversion replaces or interfaces with. The supplied kit is an unbranded aftermarket 44 mm conversion kit and is not described as a Genuine Yamaha part.\u003c\/p\u003e\n\n\n\u003ch3\u003eReference Specifications\u003c\/h3\u003e\n\u003ctable\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003cth\u003eNominal displacement\u003c\/th\u003e\n\u003ctd\u003e60 cc big-bore conversion\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eBore\u003c\/th\u003e\n\u003ctd\u003e44.0 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eStandard PW50 bore\u003c\/th\u003e\n\u003ctd\u003e40.0 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003ePW50 stroke\u003c\/th\u003e\n\u003ctd\u003e39.2 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eReference cylinder outside width\u003c\/th\u003e\n\u003ctd\u003eapproximately 51 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eReference cylinder total height\u003c\/th\u003e\n\u003ctd\u003eapproximately 87.5 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eReference cylinder section length\u003c\/th\u003e\n\u003ctd\u003eapproximately 64 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eEngine type\u003c\/th\u003e\n\u003ctd\u003eAir-cooled 2-stroke single-cylinder application\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\n\n\u003ch3\u003eWhat's Included\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e1 × 44 mm cylinder block\u003c\/li\u003e\n\u003cli\u003e1 × cylinder head\u003c\/li\u003e\n\u003cli\u003e1 × 44 mm piston\u003c\/li\u003e\n\u003cli\u003e1 × piston ring set\u003c\/li\u003e\n\u003cli\u003e1 × piston pin\u003c\/li\u003e\n\u003cli\u003e2 × piston circlips\u003c\/li\u003e\n\u003cli\u003e1 × small-end \/ needle bearing\u003c\/li\u003e\n\u003cli\u003e1 × cylinder-head gasket\u003c\/li\u003e\n\u003cli\u003e1 × cylinder-base gasket\u003c\/li\u003e\n\u003cli\u003e4 × cylinder studs\u003c\/li\u003e\n\u003cli\u003e4 × stud nuts\u003c\/li\u003e\n\u003cli\u003e1 × spark plug\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003eContents are based on the supplied kit listing and matching 44 mm PW50\/QT50 big-bore kit specifications.\u003c\/p\u003e\n\n\n\u003ch3\u003eImportant Fitment Information\u003c\/h3\u003e\n\u003cp\u003e\u003cstrong\u003eConfirm the original engine configuration before ordering.\u003c\/strong\u003e QT50 specification and previous engine modifications can vary, so match the original cylinder, head, stud spacing and gasket profile before fitting. This is a 44 mm big-bore conversion kit, not a standard 40 mm replacement cylinder. Compare the cylinder, stud pattern, gasket shape and top-end components with the engine currently fitted.\u003c\/p\u003e\n\n\n\u003ch3\u003eCondition\u003c\/h3\u003e\n\u003cp\u003e\u003cstrong\u003eNew.\u003c\/strong\u003e Unused aftermarket replacement \/ upgrade engine components.\u003c\/p\u003e\n\n\n\u003ch3\u003eDelivery \u0026amp; Returns\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eFree UK delivery with an estimated 2–3 working-day service\u003c\/li\u003e\n\u003cli\u003e30-day returns, subject to the item being returned in its original condition\u003c\/li\u003e\n\u003c\/ul\u003e\n","brand":"Unbranded","offers":[{"title":"Default Title","offer_id":57435344863607,"sku":"01220-ENG","price":43.0,"currency_code":"SHP","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0528\/8771\/6007\/files\/20260831_151637_da322182-68ba-48c1-bf18-057c097934f5.png?v=1788428684","url":"https:\/\/www.motomaniauk.com\/products\/yamaha-qt50-60cc-big-bore-cylinder-head-piston-kit-44mm-1979-1987","provider":"Moto Mania UK","version":"1.0","type":"link"}