Ihave a3540thatrecently has been difficult to start...Ibelieve itisthe HST switch.I have to "wiggle" thefoot peddle back and forth to start the tractor, and the tractor slowly crawls forward or reverse depending on which directionwas last headed...DANGEROUS. The tractorshuts off i get off or stand up,so ibelieve the seat safety switch is working fine. What is needed for repair and is this difficult? Reason Iask is I'vehad several strokes earlier this year,as evidencedbymy typing here. THNX