Not sure what "PTO arms" you are referring to, but assume you are talking about the 3-point lift arms supported by the rock shaft. There is likely a valve (knob or lever control) that can be opened to allow the lift arms to drop faster. Check the manual, or look around under the seat for such a knob. PS: PTO stands for Power Take Off and is the drive shaft for powering equipment such as a rotary cutter. I hope this helps.