Adjusting valves on a 90cc, is this normal?

[WEATHERBY460]

When adjusting valves on a 90cc, is it normal for the rocker arm to move back and forth? If so, do you adjust the valves when the rocker arm is up or down? thanks

[shortline10]

Yes the rockers will move a little side to side . motor needs to be at top dead center to adjust the valves , meaning the piston is all the way to the top of the cylinder and the valves are closed then adjust .