The little open space: 这个叫凸轮轴减压器,作用是当摩托车起动时,让排气门打开,使起动转速快速达到规定转速,当车发动以后,这 个减压器就不起作用了
The function of the camshaft regulator (凸轮轴减压器) is only to open the exhaust valve when the motocycle starts, so that the motobike can accelerate from its start speed until it reaches a steady fast speed.