Motorcycle 90cc Big Bore Cylinder Kit and Crankshaft for TX 50 Supermoto 2-Stroke AM6 Minarelli Engine This cylinder kit features a bore diameter of 49mm and is equipped with a piston pin diameter of 12mm.Designed as an upgrade for 2-stroke AM6 engines, the big bore kit increases engine displacement to 90cc for improved performance.The package includes a cylinder, piston, gaskets, and a matching crankshaft built to work together for balanced.Compatible with TX 50 Supermoto models from 2009 onward and 50 Supermoto models from 2007 to 2008, both using the AM6 Minarelli engine platform.This is a direct bolt-on assembly for the specified models but may require adjustments to carburetion and exhaust tuning for performance.