I bought a used snapper 48 inch walk behind for some smaller yards last month. This was my first walk behind that I have ever used. It's in really great shape , great hydros, really cuts nice, but I have problems with spinning the wheels a lot and it doesn't take much to pop the deck in the air. I put new tires on it thinking it would help stop the spinning but, it hasn't. I read about putting weight or some type of ballast on the deck but the article wasn't to informative . Can I get some input from you folks to correct this!