First, remove the upper body of the carburetor. The oil level in the float chamber should be 22mm from the upper plane of the carburetor. If it does not meet the requirements, it should be further checked to adjust the position of the float. The specific method is to remove the chemical oil. The upper body is turned over and flattened so that the float is facing up. At this time, the height of the float determines the level of the oil level in the float chamber. Therefore, the position of the float can be measured to determine the level of the oil level when the carburetor is working. The minimum distance between the boss of the upper plane of the float and the lower plane of the upper part of the carburetor is required to be 8 mm. If the distance is less than 8 mm, the oil level of the float chamber is too high when the carburetor is working, and vice versa. Then push the float up to the highest position, which is the lowest position of the float when the carburetor is working. The distance between the float arm and the needle valve should be 1.6mm.