Time Master

[RYANS']

My time Master mower cuts high. At the lowest setting the chassis rubs the ground. And grass hieght is about an inch and a quarter. How can I lower the blade hieght without compromising performance? I thought about putting a shim on the blade and then re-attaching it so the blade is then level with the bottom of the deck. The next cutting hieght level is 2 1/4 inched I think. Too high for me. I cut commercially, small residential properties, and some larger 1/2 acre sections. The small properties I want to cut the same hieght as my 18 inch lawn master can do which by looking at the cut grass is about 1/2 inch high. Any suggestions, get her done.