Features: With the latest V.2 Cylinder kit series from NARAKU, we can offer a more advanced product. As a 4 stroke cylinder is effectively just a hole, the emphasis on technological development was placed on the piston and compression. The piston has 2 additional CNC-machined oil grooves in the piston skirt, which collects engine oil to lubricate the cylinder bore and improve characteristics in extreme circumstances. The molybdenum coating aids the crucial running-in period. 2 oil recesses and a groove at each bearing point ensure the gudgeon pin is adequately lubricated. The compression ratio has been specially calibrated to the requirements of everyday running. Narakus high quality and very good power delivery cap off this cylinder kit. The kit can be used with the original carburettor, but we recommend changing the main jet. All parts necessary for installation are included. For Sym scooters this kit is only suitable for the GY6 139QMB engine version and not the XS1P139QMB, AV05W o