I bought a 21" Honda Harmony a couple months ago and at the time it cut great. After the blades dulled a little, the quality of cut got worse, to the point where there would be rows of partially-cut grass leftover from overlapping the mowing path. I bought new blades and a bench grinder and sharpened them all. The cut didn't improve- even with very sharp blades (I did dip the blades in water often while grinding to keep the blade temper), and overlapping a lot while mowing (so the deck goes over the wheel tracks), and with dry St. Augustine grass, not only are there errant blades that are untouched after going under the deck, but around the edges of each mowing path, there are semi-cut paths of grass, whole ROWS of uncut grass! In other words, the mower is cutting the grass in these rows but it's a noticeable inch or so higher than the rest of the cut grass. The underside of the deck is clean, deck height set as usual, and I'm mowing properties poorly now that I've mowed when the Honda was brand-new that looked great then. I'm dumbfounded.. searching the forums didn't turn up much info. Has anyone experienced this or have a suggestion? The grass that is cut well looks like it was cut with a scissors, so I know the blades are sharp.. but something is very wrong. I'm not going to change mowers anytime soon since this is a small business I'm running while in college and the Honda was $500.. and it used to cut perfectly!