I am just starting to expand my biz and I got a 48" MTD Pro w/b. I am not satisfied with its cut and am wondering if there is any way that I can adjust tension or something. When cutting grass any higher than three or four inches, it tends to leave a strip of unmowed grass. I did a job today and I had to cut everything twice to get a nice job. I've seen other companies buzzing right through grass like that no problem. And they don't leave strips of grass. Any help will be appreciated!!