I have a 48" Kees wb with a 12.5 Kaw on it. It runs great, but when I engage the blades, the thing sounds like it is gonna blow up. REALLY loud. I am new to commercial wb's. How loud is the average mower once you engage the blades? I am afraid to run this at a customers house. I think they will run me off. It isn't knocking or anything, it is just loud. It sounds like it may have bearing noise or something. Any ideas? I am gonna have to use the ol trusty Lawn boy untill I get this fixed.