Check the listing for details. Scooter GY6 150cc Taida 63mm Forged Dome Piston Big Bore For 8.2mm Stroke 4 Valv. Condition: New. Listed at 215.00 USD. *63mm TAIDA ceramic CYLINDER forged dome (4mm) piston for 4 valve head. HEAD GASKET, AND 2 BASE GASKETS . Boring of the case is required. Made for 8.2mm stroker crank. NOT FOR GOKARTS OR ATV'S REGARDLESS IF THEY HAVE A GY6 ENGINE. WILL NOT FIT ANY KYMCOS. *FOR STOCK GY6 BLOCK WITH 54mm SPACING ONLY* OUTER CYLINDER DIAMETER 62.7mm CYLINDER BORE 61mmCYLINDER HEIGHT 69.3mm *YOU WILL NEED TO RE-JET YOUR OLD CARBURETOR* *WE SUGGEST GETTING A LARGER 26-28mm or 30mm CVK CARBURETOR*WITH ACCELERATOR PUMP AND RE-JET TO SUIT INSTALLATION BY PROFESSIONAL IS HIGHLY RECOMMENDED. DO NOT USE STROKER CRANKSHAFTS WITH THESE KITS PER TAIDA. ONCE INSTALLED THERE ARE NO REFUNDS OR EXCHANGES. ANY RETURNS MUST INCLUDE ALL ORIGINAL PACKAGING IN PERFECT CONDITIONBUYER PAYS RETURN SHIPPING. WE DO NOT REFUND SHIPPING. ITEM SHIPS USPS PRIORITY