This complete diaphragm carburettor is designed for Chinese chainsaws of the 4500 series and is responsible for producing the optimal mixture of fuel and air. Precise metering of the fuel mixture directly affects stable engine idling, quick throttle response and reaching maximum power under load. It is made of a light and durable aluminium alloy resistant to vibration and temperature fluctuations, while the internal diaphragms are made of special rubber resistant to the aggressive properties of modern fuels. Timely replacement of the complete carburettor is necessary when the internal channels and jets become clogged due to prolonged standing of old fuel or when the body has suffered mechanical damage. Using a faulty carburettor can lead to engine overheating because of an overly lean mixture, or to choking and fuel flooding. The component is supplied as a complete unit ready for direct installation, which allows the saw to be quickly returned to factory operating mode. Technical specifications (dimensions): Manufacturer/Brand: high-precision replacement brand Carburettor type: diaphragm type Opening diameter on the air filter side: 19 mm Opening diameter on the cylinder side (intake throat): 15,5 mm Distance between the centres of the mounting holes (both sides): 25,5 mm Connecting hose diameter: 4 mm Compatible repair kit (service kit): US-18149 Part type: high-precision replacement part Compatibility (list of models and application): Intended for all types of Chinese G-4500 model chainsaws of 45 cc. Provides efficient fuel supply to the engine while cutting wood, clearing land and preparing firewood in the field. The time for replacement comes when the saw runs improperly, loses power, floods fuel, does not respond to adjustment of the mixture screws, or when the engine cannot start despite good ignition and compression.