Here is an excellent tip on blade adjustment that I rcvd from a greenskeeper:

Found your article interesting, as I was a superintendent in Northern California for a long time. I have some advice for you regarding setting height of cut. Height of cut is determined by the distance between the bottom of the rollers and the top edge of the bedknife. The best way to set this distance is to use a bedknife setting tool, available from most reel mower manufacturers (McClane might have one; I know Toro and Jacobsen do). You can also make it yourself; it's very simple. All you need is a flat piece of metal a few inches longer than the distance between the bottoms of the rollers. 1/4" or 3/8" thick by 2" or 3" wide steel is what's used in the commercial ones. Place the piece flat across the front and back rollers and figure about where along its length the bedknife edge is. Mark at that point. Drill and tap a 1/4-20 hole in the center of the piece at that point along its length. Insert into the hole a round head or panhead screw. The screw is threaded in until the distance between the underside of the head and the flat piece is the same as the cutting height. A nut is placed on the far side and tightened (the screw must be long enough to project the width of the nut through the piece at maximum cutting height). So now what you have is a flat piece of metal with a screw sticking up out of it the exact distance you need to set height of cut. Now with the tool bridging the distance between the rollers you adjust the bedknife so it just contacts the underside of the screw. Do both ends of the bedknife and double check when you're done. Two warnings: (1) Do not adjust with the tool in place. If you go too far you'll bend the bedknife at that spot. Adjust a little, then check with the tool. Adjust a little more, then check again. After you're done, check one more time to be sure nothing moved. (2) The actual cutting height is often lower than what is set, due to the weight of the machine. The softer the green, whether from moisture or thatch, the more pronounced the difference between the bench setting and the actual height of cut. Experiment to find what the correct bench settings are for different conditions. Another comment: In theory, when a mower is sharp, there should be no actual contact between reel and bedknife when adjusted close enough to cut a single sheet of newspaper. In reality, there should be no more than very lght contact. Heavier contact indicates backlapping is needed. If backlapping is ineffective, sharpening by grinding is needed. Backlapping is great for maintaining an edge, but is ineffective for restoring an edge once it's lost. If you backlap regularly. you may never have to have your mower sharpened. I used to sharpen my mowers once a year because of accumulated damage from coins, lost spikes, bits of pea gravel, etc. During the growing season I would backlap once a week. You may not need to backlap more than once every 4-6 weeks.