Big Bore aluminium cylinder kit with 155cc capacity for Yamaha Cygnus and BWK 125cc 5ML engines. This cylinder is an aluminium / ceramic cylinder with a hard chrome-plated 59mm cylinder bore. Aluminium cylinders have better heat dissipation than standard 4-stroke cast iron with steel bush. This cylinder kit can be operated with the original cylinder head. Another highlight of this Naraku cylinder kit is the forged piston. For much more durability and reduced friction. The increased piston head also ensures a higher compression. Supplied as shown.