This paper introduces four methods to adjust the fuel injection needle of motorcycle carburetor to save fuel.

1, the oil level in the float chamber should be relatively low. The fuel in the float chamber enters the carburetor throat through the main orifice and mixes with air to form a combustible mixture. The purpose of moderately lowering the liquid level is to reduce the pressure difference.

2. The main measuring hole is divided into two types: fixed and adjustable. If it is a fixed main metering hole, one or two thin copper wires can be wound in the metering hole. In the case of less fuel throughput, the rotary needle can be screwed to the end first, and then rotated counterclockwise for about one and a half weeks to adjust. The reasonable reduction of mixture concentration is mainly based on the stable operation of the engine, and there can be no setback when the car accelerates and carburetor backfire. It may take several adjustments to reach a reasonable level.

3. Under normal circumstances, try not to step on the accelerator to the end, so as to achieve the purpose of saving fuel. Throttle opening within two-thirds is the leanest and most fuel-efficient state.

4. Adjusting the screw on the right side of the carburetor can reduce the idle speed (counterclockwise adjustment) to save fuel.