125 how to adjust the throttle of motorcycle?

This is top dead center. It should be noted that when it is aligned with T, there are two top dead centers: if it corresponds to compression top dead center at this time, one more turn is exhaust top dead center. Remove the valve cover and determine the compression top dead center through observation and exploration. When it is at the compression top dead center, both valve screws are in the down position. If the valve clearance is not tight, you can shake the valve clearance up and down with your hands.