Curved beam motorcycle, after the throttle is unscrewed, it does not return. It is found that the bucket of the column carburetor (Figure 1) is stuck. Barrel (Figure 2).

The correct name of "bucket" is "throttle valve", which itself does not need oil lubrication. If the throttle valve is stuck and cannot return, first check whether the throttle valve is installed correctly, deformed or worn, and whether the oil needle under the throttle valve is normal. If inferior gasoline is used, it will also produce sticky substances at the contact part between the throttle and carburetor, which will make the throttle stuck. It is necessary to thoroughly clean the carburetor and even the whole oil supply system in order to completely eliminate the fault. It is useless to lubricate with oil only before the fault is completely solved.