I have a great dane super surfer and a sckamper. the walk behind cuts great, but the s.s. isnt cutting quite as good as i would like(not the very most outside edges of the deck but everything else in between) if i cut in two directions it great. im just wondering if it could be a timing issue. i have also started sharping my own blades(i used to sharpen my blades before at another huge lco i used to work for before,no problems) just wondering how important this timing issue is and if anyone knows weather G.D. require timing. would a high lift blade work better for standard mowing?