Features: 1.The carburetors are the heart of the engine, and many of the faults they bring to the machinery and equipment can be removed by careful cleaning. 2.Made of superior quality aluminium alloy material, strong corrosion resistance, rugged and durable. 3.19mm /0.75in carburetor with 58mm/2.28in blue air filter, and the screw on the side of the carburetor is for the idle. 4.Normally for 6mm/0.24in jet, you can start with start with the smallest size jet, the jet does not need to be torqued down with a great deal of force. 5.Racing carburetor is perfectly fit for 2 Stroke 49cc 66cc 70cc 80cc engine motorized bicycle. Specification: Item Type: Carburetor Air Filter Set_x000D_ Material: Aluminum alloy_x000D_ Quantity: 1 set (with blue air filter)_x000D_ Carburetor Diameter: Approx. 19mm/0.75in_x000D_ Application: Used to replace retrofit carburetor and improve engine fuel performance_x000D_ _x000D_ Fitment: Fit for 2 Stroke 49cc 66cc 70cc 80cc Engine Motorized Bicycle PackageList: 1 x Carburetor 1 x Air Filter 1 x Fixed Flange Hoop Note: If you want to replace the NT carburetor that comes with the 66/80cc bicycle engine, you must wrap several layers of cord around it. If you are at a higher altitude, you may need to change the nozzle size of this carburetor to operate appropriately.