I purchased an 05 (new) Super Z 52"/25hp Kaw about 3 months ago and I have nothing but positive things to say about this awesome mower, however, this is just one thing I'm having an issue with and that's the loud roar of the Fusion blades. Recently I removed the blades, cranked the machine and engaged the PTO - all was quiet. I then checked the blades just to make sure they were balanced and installed the left blade, cranked machine, engaged PTO - still no objectionable noise level. Did the same with center blade (left blade still on) - again noise level acceptable - then - I installed the right blade (blade nearest discharge chute) - WOW - roar out the roof! It's not a vibration - it's a roar that penetrates my foam ear plugs and over the ear hearing protector baffles. Is this just the nature of the beast or do I have a situation that needs to be addressed? FYI - I owned a Super Mini Z 19/52 and never had this problem. Thanks to all for your input.