I have owned these mowers for many years and never paid attention to the results as I have recently . My son-n law was discussing with me that the mower on his was mowing uneven , and didn`t know what was causing this . That caused me to focus more interest in my results when mowing. I discovered the same results were being delivered with mine . It seems the mower cuts at a different height for the center blade which causes a striped effect for the appearance . Can anyone offer any info on the situation ? One more question I am interested in an answer to is I replaced a pulley on the blade ,now the grease fitting does not take grease . is something misaligned on the shaft??