{"product_id":"naraku-qmb139-52-4mm-performance-cylinder-head-kit-1","title":"Naraku 52.4mm Performance Cylinder \u0026 Head Kit – QMB139 – Part #NK100.52","description":"\u003cp\u003eNaraku 50cc QMB139 4-stroke 52.4mm, Racing Big Bore Cylinder and Head Kit. Kit includes cylinder, piston, rings, piston pin, cir clips, cylinder head, head gasket, and base gasket.\u003c\/p\u003e\n\u003cp\u003eWhen used in conjunction with a stock stroke of 41.4mm the total displacement comes out to 89.3cc! When used with a 44mm stroker crank, total displacement measures 94.9cc!\u003c\/p\u003e\n\u003cp\u003ePlease see our Warranty \u0026amp; Returns Policy.\u003c\/p\u003e\n\u003cp\u003ePlease note: replaces Cylinder Heads with 64mm Valves (Short Valve Style). Please see Related Items if you need 64mm valves. You may need to modify your engine case to accommodate the larger cylinder.\u003c\/p\u003e\n\u003cp\u003eUpgrades to 89.3cc\u003cbr\u003eCylinder Bore: 52.4mm\u003cbr\u003eCylinder Sleeve Outer Diameter: 54.4mm\u003cbr\u003eWrist Pin Diameter: 13mm\u003cbr\u003eTotal Piston Height: 36.3mm\u003cbr\u003eCompression Height (from center of wrist pin hole to top edge of piston): 20mm\u003cbr\u003eNon-emissions style head\u003cbr\u003eIntake valve: 23mm\u003cbr\u003eExhaust valve: 20mm\u003cbr\u003eIntake Port Diameter: 20.8mm\u003cbr\u003eExhaust Port Diameter: 18.7mm\u003cbr\u003eUses Short 64mm Valve Stems\u003cbr\u003eQMB139 50cc\/49cc , Various unlisted makes\/models\u003c\/p\u003e\n\u003cp\u003eThis product is not intended for use on public roads or land.\u003c\/p\u003e","brand":"Moped Garage Hawaii","offers":[{"title":"Default Title","offer_id":42569488466038,"sku":"NK100.52 137-4","price":315.0,"currency_code":"USD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0079\/5361\/2855\/files\/137-4.jpg?v=1758075344","url":"https:\/\/jppowersports.com\/products\/naraku-qmb139-52-4mm-performance-cylinder-head-kit-1","provider":"Moped Garage Hawaii","version":"1.0","type":"link"}