I have a 20/52 fastrak and when I mow 3" It leaves a trail of grass where i just mowed. No the grass is not wet and I am not going 100mph. It does get better at 3.5" but is this dull blades or too much build up under the deck. I have the stock blades on, and it just started to do this. Is it also possible that the grass is just to long, I don' t think so. It does this even if i go sloooow. Also should I get new blades, gator or something. I am a homeowner with 2 acres. Also if I mower 2 acres a week how often should I sharpen the blades, I know it may depend on different things, but just a guess would be fine. Mark.