Bore and Stroke: 52mm x 40mm. New 52mm cylinder. Bicycle Engine Kits including as follows parts Engine Type: Single cylinder, air-cooled,2-stroke. Gas motor 1 pc. Sprocket Install Kit 1set. Mixing Ratio of Fuel(90#) and Engine Oil: 16: 1 for New sets, 20: 1 after Running 500Km.
