I bought this used to cut my 20 acre yard.  (I bought this to replace my older IS3000z.)  At first, I thought the 3100 just had sensitive steering which I thought I could easily adjust.  But NO!  It darts uncontrollably especially on a slight incline.  It seems to get even worse at it warms up.  I feel like I'm trying to steer a darting bull around the yard.  It's nerve wracking.  Any suggestions where to pinpoint my problem?  I've had 3 different commercial zero turns and I could figure out any problem over the years.  I just don't know where to start with this.  So....motorheads....give me your suggestions.