I recently picked up a used 997 for my first ZTR. I was having a lot of problems with motion creep, left side going forward and right side in reverse. I fixed this following the user manual. The manual also states that the control levers should return to neutral when released. If I pull back and release they do slowly move forward slightly but not to neutral, pushing forward they will stay where you let go. I do not see any adjustment procedure for this. Is it an adjustment problem, hydraulic problem, bad dampers or ???