PISTON FITS MALOSSI 86cc & 2Fast 86cc & 90cc - IT DOES NOT FIT MALOSSI 90cc (Cylinder 3116919)Malossi 86cc Piston KitTECH: (Most Euro Kits)50cc = 40mm Piston Bore x 39.2mm Stroke70cc = 47.6mm Piston Bore x 39.2mm Stroke86cc = 50mm Piston Bore x 44mm Stroke90cc = 50mm Piston bore x 45.8mm Bore94cc = 52mm Piston Bore x 44mm Stroke