{"product_id":"universal-parts-qmb139-cylinder-head-kit-64mm-valves-151-242","title":"Universal Parts QMB139 Cylinder \u0026 Head Kit - 64mm Valves","description":"50cc QMB139 4-stroke Cylinder and Head Kit. Choose from 39mm, 47mm or 50mm bore in the Drop Down Box. \u003cbr\u003e\u003cbr\u003e47mm Bore Upgrades your Scooter to 72cc! \u003cbr\u003e50mm Bore Upgrades your Scooter to 81.3cc! \u003cbr\u003e \u003cp\u003eKit includes complete cylinder head, cylinder, piston, rings, piston pin, cir clips, head gasket, and base gasket.\u003cbr\u003e\u003cbr\u003e\u003cbr\u003e\u003cspan style=\"FONT-SIZE: 10pt; FONT-FAMILY: Tahoma; COLOR: black\"\u003e\u003cfont color=\"#000000\" size=\"2\"\u003e\u003cfont color=\"#0000ff\" size=\"3\"\u003e\u003cfont color=\"#ff0000\"\u003e*You may need to modify your engine case to accommodate the larger cylinder.\u003c\/font\u003e\u003c\/font\u003e\u003c\/font\u003e\u003c\/span\u003e\u003c\/p\u003e\u003cul\u003e \n\n\u003cli\u003eCylinder Bore: Choose from 39mm, 47mm or 50mm\u003c\/li\u003e\n\u003cli\u003eCylinder  Sleeve Outer Diameter: 45mm (39mm bore) \/ 52.8mm (47mm bore) \/ 53.95mm (50mm bore)\u003c\/li\u003e\n\u003cli\u003eWrist Pin Diameter: 13mm  \n\n\u003c\/li\u003e\n\u003cli\u003eTotal Piston Height: 34.4mm  \n\n\u003c\/li\u003e\n\u003cli\u003eCompression Height (from center of wrist pin hole to top edge of piston): 17.25mm\u003c\/li\u003e\n\u003cli\u003eIntake and Exhaust Valve Length: 64mm\u003c\/li\u003e\n\u003cli\u003eNon-Emissions Head\u003c\/li\u003e\n\u003c\/ul\u003eQMB139 50cc\/49cc \u003cp\u003e \u003c\/p\u003e\u003ch3 style=\"color:#983D3C;\"\u003eThis product is not intended for use on public roads or land.\u003c\/h3\u003e","brand":"Universal Parts","offers":[{"title":"50","offer_id":49986435973400,"sku":"151-242   50","price":84.0,"currency_code":"USD","in_stock":true},{"title":"47","offer_id":49986437939480,"sku":"151-242   47","price":84.0,"currency_code":"USD","in_stock":true},{"title":"39","offer_id":49986438037784,"sku":"151-242   39","price":84.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0782\/1728\/1816\/files\/151-242.webp?v=1747256187","url":"https:\/\/www.scooterworks.com\/products\/universal-parts-qmb139-cylinder-head-kit-64mm-valves-151-242","provider":"Scooterworks USA, LLC","version":"1.0","type":"link"}